Static mixers for continuous flow catalytic reactors

ABSTRACT

The present disclosure relates to catalytic static mixers comprising catalytic material. The static mixers can be configured for use with continuous flow chemical reactors, for example tubular continuous flow chemical reactors for heterogeneous catalysis reactions. This disclosure also relates to processes for preparing static mixers. This disclosure also relates to continuous flow chemical reactors comprising the static mixers, systems comprising the continuous flow chemical reactors, processes for synthesising products using the continuous flow reactors, and methods for screening catalytic materials using the static mixers.

This application is a National Stage Application of PCT/AU2016/051267,filed 21 Dec. 2016, which claims benefit of Serial No. 2015905354, filed23 Dec. 2015 in Australia and Serial No. 2016903998, filed 3 Oct. 2016in Australia and which applications are incorporated herein byreference. To the extent appropriate, a claim of priority is made toeach of the above-disclosed applications.

FIELD

The present disclosure relates to catalytic static mixers comprisingcatalytic material. The static mixers can be configured for use withcontinuous flow chemical reactors, for example tubular continuous flowchemical reactors for heterogeneous catalysis reactions. This disclosurealso relates to processes for preparing static mixers. This disclosurealso relates to continuous flow chemical reactors comprising the staticmixers, systems comprising the continuous flow chemical reactors,processes for synthesising products using the continuous flow reactors,and methods for screening catalytic materials using the static mixers.

BACKGROUND

Continuous flow chemical reactors generally comprise a tubular reactionchamber with reactant fluids being continuously fed into the reactionchamber to undergo a chemical reaction to continuously form productswhich flow out from the reaction chamber. The reaction chambers aretypically submerged in a heating/coolant fluid, for example in ashell-and-tube heat exchanger configuration, to facilitate the transferof heat to/away from the reaction.

Continuous flow reactors used in catalytic reactions typically employpacked bed reaction chambers in which the reaction chamber is packedwith solid catalyst particles that provide catalytic surfaces on whichthe chemical reaction can occur. Static mixers are used for pre-mixingof fluid streams prior to contact with the packed bed reaction chambersand downstream of these chambers to transfer heat between the centraland the outer regions of the reactor tubes. The static mixers comprisesolid structures that interrupt the fluid flow to promote mixing of thereactants prior to reaction in the packed bed reaction chambers and forpromoting desirable patterns of heat transfer downstream of thesechambers. Static mixers are also used independent of packed beds sincesome reactants do not require a catalyst to activate their reaction.

Towards improving process productivity through increased reactionyields, there is a clear need for developing enhanced static mixersand/or reaction chambers for continuous flow chemical reactors that arereadily removable and easily replaced, allow further re-designenhancement and are capable of providing more efficient mixing, heattransfer and catalytic reaction of reactant chemical and/orelectrochemical reactants.

SUMMARY

The present inventors have undertaken significant research anddevelopment into alternative continuous flow chemical reactors and haveidentified that static mixers can be provided with a catalytic surfacesuch that the resulting static mixer is capable of being used with acontinuous flow chemical reactor. It was surprisingly found thatincorporating catalytic material on the surface of additive manufacturedstatic mixers can provide catalytic static mixers that can be configuredto be readily removable and easily replaced, allow for further re-designenhancement, and provide for efficient mixing, heat transfer andcatalytic reaction of reactants in continuous flow chemical reactors.The static mixers may be provided for use with in-line continuous flowreactors as inserts or as modular packages with the static mixer as anintegral part of a section of the reactor tube itself.

Accordingly, in a first aspect there is provided a static mixer elementconfigured as a module for a continuous flow chemical reactor chamber,wherein the static mixer element comprises a catalytically activescaffold defining a plurality of passages configured for mixing one ormore fluidic reactants during flow and reaction thereof through themixer, and wherein at least a portion of a surface of the scaffoldcomprises a catalytic material for providing the surface withcatalytically reactive sites.

The static mixer element may be an additive manufactured static mixer.The static mixer element may be configured as a modular insert forassembly into a continuous flow reactor chamber. The module may providethe static mixer as an integral part of a section of the reactor.

In a second aspect there is provided a process for preparing a staticmixer element for a continuous flow chemical reactor chamber, comprisingthe steps of:

providing a static mixer element comprising a scaffold defining aplurality of passages configured for mixing one or more fluidicreactants during flow and reaction thereof through the mixer; and

applying a catalytic coating to at least a portion of the surface of thescaffold.

The step of applying the catalytic coating to at least a portion of thesurface of the scaffold may comprise or consist of electrodeposition orcold spray. The catalytic coating may comprise a catalytic materialselected from at least one of a metal, metal alloy, cermet and metaloxide, for providing the surface with a plurality of catalyticallyreactive sites. The process may comprise a step of preparing thescaffold of the static mixer by additive manufacture. The material ofthe scaffold may be selected from at least one of a metal, metal alloy,cermet and metal oxide.

In a third aspect there is provided a continuous flow chemical reactorfor use in reaction of one or more fluidic reactants comprising one ormore static mixer elements according to any embodiment as describedherein.

In a fourth aspect there is provided a system for providing a continuousflow chemical reaction comprising:

a continuous flow chemical reactor comprising a static mixer accordingto any embodiment as described herein;

a pump for providing fluidic flow for one or more fluidic reactants andany products thereof through the reactor;

one or more heat exchangers to allow for control of the temperature ofthe reactor, chamber section, static mixer, or fluidic componentsthereof; and

a controller for controlling one or more of the parameters of the systemselected from concentration, flow rate, temperature, pressure, andresidence time, of the one or more fluidic reactants, or sources orproducts thereof.

In a fifth aspect there is provided a process for synthesizing a productby catalytic reaction of one or more fluidic reactants, the processcomprising the steps of:

providing a continuous flow chemical reactor comprising a static mixerelement or system according to any embodiment as described herein;

providing at least a first fluidic reactant to the reactor via the oneor more reactant inlets;

operating the chemical reactor, or control means thereof, to provideflow and catalytic reaction of the at least first fluidic reactantthrough the static mixer; and

obtaining an output stream comprising a product of a catalytic reactionof the at least first reactant.

In a sixth aspect there is provided a method of screening a catalystmaterial for catalytic reactivity using a static mixer element or systemaccording to any embodiment as described herein, comprising the stepsof:

operating a continuous flow chemical reactor comprising the static mixerwith a predetermined catalyst material at a predetermined reactorsetting; and

determining the yield of product obtained from an output stream.

In a seventh aspect there is provided a process for design andmanufacture of a catalytic static mixer (CSM) element for a continuousflow chemical reactor chamber comprising the steps of:

designing a prototype static mixer element comprising a scaffolddefining a plurality of passages configured for mixing one or morefluidic reactants during flow and reaction thereof through the mixer;

additive manufacturing the prototype static mixer element;

applying a catalytic coating to the surface of the scaffold of theprototype static mixer element to form a prototype catalytic staticmixer (CSM) element;

testing the prototype CSM for at least one of suitability for catalyticcoating or operational performance and durability in a continuous flowchemical reactor;

redesigning the static mixer element to enhance at least one ofsuitability for catalytic coating or operational performance anddurability in a continuous flow chemical reactor; and

manufacturing the redesigned static mixer element comprising aredesigned scaffold defining a plurality of passages configured formixing one or more fluidic reactants during flow and reaction thereofthrough the mixer, and applying a catalytic coating to the surface ofthe scaffold to form the catalytic static mixer (CSM) element.

Further embodiments of the above the above aspects are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present disclosure will now be furtherdescribed and illustrated, by way of example only, with reference to theaccompanying drawings in which:

FIG. 1 shows a number of different static mixers according to someembodiments;

FIG. 2 shows a static mixer according to some embodiments;

FIG. 3 shows a schematic diagram of a cold spraying system according tosome embodiments;

FIG. 4 shows a scaffold support system for cold spraying a scaffoldaccording to some embodiments;

FIG. 5 shows a scaffold support system for cold spraying a scaffoldaccording to other embodiments;

FIG. 6 shows a support member for use with the scaffold support systemof FIG. 5 ;

FIG. 7A illustrates a process for coating static mixers according to oneexample;

FIG. 7B shows a static mixer coated in accordance with the process ofFIG. 6A;

FIGS. 8A and 8B show the difference between the coated and uncoatedsurfaces and (a cross-section respectively) of a static mixer coatedwith a catalyst using cold spray deposition, according to one example;

FIGS. 8C and 8D show detailed images of surfaces of a static mixercoated with catalytic material using cold spraying, according to oneexample;

FIGS. 9A and 9B show detailed images of surfaces of a static mixercoated with catalytic material using electro-deposition, according toone example;

FIG. 10 shows a schematic example of a continuous flow reactor systemcomprising a CSM of the present disclosure;

FIG. 11 shows influence of gas-to-liquid ratio on conversion, usingcatalyst set Ni-CS-SS-C-R1-4 according to an embodiment and oleic acidas substrate, solvent: EtOAc, pressure=16 bar, T=140° C., total flowrate=2.30 ml/min, τ=6.5 min;

FIG. 12 shows influence of reactor pressure on conversion, using threedifferent catalyst sets according to some embodiments and vinyl acetateas substrate, solvent: EtOH, T=140° C., total flow rate=2.30 ml/min,G/L=5.00, τ=4.6 to 5 min;

FIG. 13 shows activation study using catalyst set Pt-EP-Ti-A-P1-5 andvinyl acetate as substrate, solvent: EtOH, pressure=16 bar, T=140° C.,total flow rate=3.00 ml/min, G/L=5.00, τ=4.7 min;

FIG. 14 shows a comparison of six different catalyst sets (see Table 1)for the hydrogenation of oleic acid (yellow bars) and vinyl acetate(blue bars); for OA the following conditions were used: T=140° C., p=16bar, G/L=3.6, τ=6 min; for VAc the following conditions were used:T=140° C., p=16 bar, G/L=5, τ=5 min;

FIG. 15 shows a reduction of benzyl cyanide to phenylethylamine using anickel cold spray coating on a stainless steel aluminium alloy(Ni-CS-SS-A-2-8) with a 0.5 mL/min liquid flow rate, 5 mL/min hydrogengas flow rate, 24 bar at 120° C.; and

FIG. 16 shows that conversion of vinyl acetate to ethyl acetate using anickel cold spray coating on a stainless steel aluminium alloy(Ni-CS-SS-A-2-8) and a 12-set reactor module in series with atemperature of 120° C.

FIG. 17 shows tracer transport in laminar and turbulent flows.

DETAILED DESCRIPTION

The present disclosure describes the following various non-limitingembodiments, which relate to investigations undertaken to identifystatic mixers capable of being readily removable and easily replaced,allowing further re-design enhancement and providing efficient mixing,heat transfer and catalytic reaction of reactants for use withcontinuous flow chemical reactors. It was surprisingly found thatincorporating catalytic material on the surface of additive manufacturedstatic mixers can provide efficient mixing, heat transfer and catalyticreaction of reactants in continuous flow chemical reactors. Thecontinuous flow chemical reactors comprising the static mixers developedusing additive manufacturing can also be operated at commerciallyrelevant flow rates, and may also provide such operation with manageableback pressures (an indicator of the resistance to flow) as described infurther detail below. According to at least some embodiments describedherein, the static mixers can advantageously be configured and used within line continuous flow reactors as inserts or as modular packages withthe static mixer as an integral part of a section of the reactor tubeitself. Further advantages of the static mixers, at least according tosome embodiments as disclosed herein, is that they can be configured andused with single pass in-line continuous flow reactors. The staticmixers may be tubular and used with tubular continuous flow chemicalreactors.

Static mixers have traditionally been directed to mixing fluidiccomponents, and when used with chemical reactors, as pre-mixing elementsprior to reactions using packed bed systems. As mentioned, chemicalreactors typically use packed bed systems and therefore are not directedto higher flow rate operations in which the present static mixers canoperate.

Compared to current heterogeneous catalysis systems, such as packedbeds, the present static mixers have been shown to provide variousadvantages. Additive manufacturing technology (i.e. 3D printing) enablesflexibility in re-design and configuration of the static mixers,although presents other difficulties and challenges in providing robustcommercially viable scaffolds that can be catalytically coated tooperate under certain operational performance parameters of continuousflow chemical reactors, such as to provide desirable mixing and flowconditions inside the continuous flow reactor, and enhanced heat andmass transfer characteristics and reduced back pressures compared topacked bed systems. In addition, electro-deposition and cold spraytechniques have been found to be surprisingly suitable for catalyticallycoating the static mixers and were suitable for application with a widevariety of metal catalysts.

As described further below, the static mixers can be configured aselements to provide inserts for use with in-line continuous flow reactorsystems. The static mixers can also provide heterogeneous catalysis,which is of significant importance to chemical manufacturing and isbroad ranging including the production of fine and specialty chemicals,pharmaceuticals, food and agrochemicals, consumer products, andpetrochemicals. Further details and embodiments of the static mixerinserts are described below.

Specific Terms

“Element” refers to an individual unit that can be used together withone or more other components in forming a continuous flow reactorsystem. Examples of an element include an “insert” or “module” asdescribed herein.

“Single pass reactor” refers to a reactor used in a process or systemwhere the fluidic components pass through the reactor on a singleoccasion and are not recycled back through the reactor from which theyhave already passed through.

“Aspect ratio” means the ratio of length to diameter (L/d) of a singleunit or element.

General Terms

Throughout this specification, unless specifically stated otherwise orthe context requires otherwise, reference to a single step, compositionof matter, group of steps or group of compositions of matter shall betaken to encompass one and a plurality (i.e. one or more) of thosesteps, compositions of matter, groups of steps or groups of compositionsof matter. Thus, as used herein, the singular forms “a”, “an” and “the”include plural aspects unless the context clearly dictates otherwise.For example, reference to “a” includes a single as well as two or more;reference to “an” includes a single as well as two or more; reference to“the” includes a single as well as two or more and so forth.

Those skilled in the art will appreciate that the disclosure herein issusceptible to variations and modifications other than thosespecifically described. It is to be understood that the disclosureincludes all such variations and modifications. The disclosure alsoincludes all of the steps, features, compositions and compounds referredto or indicated in this specification, individually or collectively, andany and all combinations or any two or more of said steps or features.

Each example of the present disclosure described herein is to be appliedmutatis mutandis to each and every other example unless specificallystated otherwise. The present disclosure is not to be limited in scopeby the specific examples described herein, which are intended for thepurpose of exemplification only. Functionally-equivalent products,compositions and methods are clearly within the scope of the disclosureas described herein.

The term “and/or”, e.g., “X and/or Y” shall be understood to mean either“X and Y” or “X or Y” and shall be taken to provide explicit support forboth meanings or for either meaning.

Throughout this specification the word “comprise”, or variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated element, integer or step, or group of elements, integers orsteps, but not the exclusion of any other element, integer or step, orgroup of elements, integers or steps.

It will be clearly understood that, although a number of prior artpublications are referred to herein, this reference does not constitutean admission that any of these documents forms part of the commongeneral knowledge in the art, in Australia or in any other country.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. In case of conflict, the presentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

Static Mixers

It will be appreciated that the static mixers can provide an integralelement for a chemical reactor chamber. The static mixer element for acontinuous flow chemical reactor chamber may comprise a catalyticallyactive scaffold defining a plurality of passages configured fordispersing and mixing one or more fluidic reactants during flow andreaction thereof through the mixer. It will be appreciated that at leasta substantial part of the surface of the scaffold may comprise acatalytic material. The catalytic material may be selected from at leastone of a metal, metal alloy, cermet and metal oxide, for providing thesurface of the scaffold with catalytically reactive sites.

The static mixer may be provided as one or more elements each configuredfor inserting into a continuous flow chemical reactor or reactor chamberthereof. The static mixer element may be configured as a modular insertfor assembly into a continuous flow chemical reactor or chamber thereof.The static mixer element may be configured as an insert for an in-linecontinuous flow chemical reactor or chamber thereof. The in-linecontinuous flow chemical reactor may be a recycle loop reactor or asingle pass reactor. In one embodiment, the in-line continuous flowchemical reactor is a single pass reactor.

The static mixer element may be configured for enhancing mixing and heattransfer characteristics for redistributing fluid in directionstransverse to the main flow, for example in radial and tangential orazimuthal directions relative to a central longitudinal axis of thestatic mixer element. The static mixer element may be configured for atleast one of (i) to ensure as much catalytic surface area as possible ispresented to the flow so as to activate close to a maximum number ofreaction sites and (ii) to improve flow mixing so that (a) the reactantmolecules contact surfaces of the static mixer element more frequentlyand (b) heat is transferred away from or to the fluid efficiently. Thestatic mixer element may be provided with various geometricconfigurations or aspect ratios for correlation with particularapplications. The static mixer elements enable fluidic reactants to bemixed and brought into close proximity with the catalytic material foractivation. The static mixer element may be configured for use withturbulent flow rates, for example enhancing turbulence and mixing, evenat or near the internal surface of the reactor chamber housing. It willalso be appreciated that the static mixer element can be configured toenhance the heat and mass transfer characteristics for both laminar andturbulent flows.

The configurations may also be designed to enhance efficiency, degree ofchemical reaction, or other properties such as pressure drop (whilstretaining predetermined or desired flow rates), residence timedistribution or heat transfer coefficients. As previously mentioned,traditional static mixers have not been previously developed tospecifically address enhanced heat transfer requirements, which mayresult from the catalytic reaction environments provided by the presentstatic mixers.

The configuration of the scaffold, or static mixer, may be determinedusing Computational Fluid Dynamics (CFD) software, which can be used forenhancing the configuration for mixing of reactants for enhanced contactand activation of the reactants, or reactive intermediates thereof, atthe catalytically reactive sites of the scaffold. The CFD basedconfiguration determinations are described in further detail in sectionsbelow.

The static mixer element, scaffold, or reactor chamber thereof, may beformed by additive manufacturing, as also described in sections below.The static mixer may be an additive manufactured static mixer. Additivemanufacturing of the static mixer and subsequent catalytic coating canprovide a static mixer that is configured for efficient mixing, heattransfer and catalytic reaction (of reactants in continuous flowchemical reactors), and in which the static mixer may be physicallytested for reliability and performance, and optionally furtherre-designed and re-configured using additive manufacturing (e.g. 3Dprinting) technology. Additive manufacturing provides flexibility inpreliminary design and testing, and further re-design andre-configuration of the static mixers to facilitate development of morecommercially viable and durable static mixers.

The static mixer element may be provided in a configuration selectedfrom one or more of the following general non-limiting exampleconfigurations:

-   -   open configurations with helices;    -   open configurations with blades;    -   corrugated-plates;    -   multilayer designs;    -   closed configurations with channels or holes.

In one embodiment, the scaffold of the static mixer may be provided in amesh configuration having a plurality of integral units defining aplurality of passages configured for facilitating mixing of the one ormore fluidic reactants.

In another embodiment, the static mixer element may comprise a scaffoldprovided by a lattice of interconnected segments configured to define aplurality of apertures for promoting mixing of fluid flowing through thereactor chamber. The scaffold may also be configured to promote bothheat transfer as well as fluid mixing.

In various embodiments, the geometry or configuration may be chosen toenhance one or more characteristics of the static mixer element selectedfrom: the specific surface area, volume displacement ratio,line-of-sight accessibility for cold-spraying, strength and stabilityfor high flow rates, suitability for fabrication using additivemanufacturing, and to achieve one or more of: a high degree of chaoticadvection, turbulent mixing, catalytic interactions, and heat transfer.

In some embodiments, the scaffold may be configured to enhance chaoticadvection or turbulent mixing, for example cross-sectional, transverse(to the flow) or localised turbulent mixing. The geometry of thescaffold may be configured to change the localised flow direction or tosplit the flow more than a certain number of times within a given lengthalong a longitudinal axis of the static mixer element, such as more than200 m⁻¹, optionally more than 400 m⁻¹, optionally more than 800 m⁻¹,optionally more than 1500 m⁻¹, optionally more than 2000 m⁻¹, optionallymore than 2500 m⁻¹, optionally more than 3000 m⁻¹, optionally more than5000 m⁻¹. The geometry or configuration of the scaffold may comprisemore than a certain number of flow splitting structures within a givenvolume of the static mixer, such as more than 100 m⁻³, optionally morethan 1000 m⁻³, optionally more than 1×10⁴ m⁻³, optionally more than1×10⁶ m⁻³, optionally more than 1×10⁹ m⁻³, optionally more than 1×10¹⁰m⁻³.

The geometry or configuration of the scaffold may be substantiallytubular or rectilinear. The scaffold may be formed from or comprise aplurality of segments. Some or all of the segments may be straightsegments. Some or all of the segments may comprise polygonal prisms suchas rectangular prisms, for example. The scaffold may comprise aplurality of planar surfaces. The straight segments may be angledrelative to each other. Straight segments may be arranged at a number ofdifferent angles relative to a longitudinal axis of the scaffold, suchas two, three, four, five or six different angles, for example. Thescaffold may comprise a repeated structure. The scaffold may comprise aplurality of similar structures repeated periodically along thelongitudinal axis of the scaffold. The geometry or configuration of thescaffold may be consistent along the length of the scaffold. Thegeometry of the scaffold may vary along the length of the scaffold. Thestraight segments may be connected by one or more curved segments. Thescaffold may comprise one or more helical segments. The scaffold maygenerally define a helicoid. The scaffold may comprise a helicoidincluding a plurality of apertures in a surface of the helicoid.

The dimensions of the static mixer may be varied depending on theapplication. The static mixer, or reactor comprising the static mixer,may be tubular. The static mixer or reactor tube may, for example, havea diameter (in mm) in the range of 1 to 5000, 2 to 2500, 3 to 1000, 4 to500, 5 to 150, or 10 to 100. The static mixer or reactor tube may, forexample, have a diameter (in mm) of at least about 1, 5, 10, 25, 50, 75,100, 250, 500, or 1000. The static mixer or reactor tube may, forexample, have a diameter (in mm) of less than about 5000, 2500, 1000,750, 500, 250, 200, 150, 100, 75, or 50. The aspect ratios (L/d) of thestatic mixer elements, or reactor chambers comprising the static mixerelements, may be provided in a range suitable for industrial scale flowrates for a particular reaction. The aspect ratios may, for example, bein the range of about 1 to 1000, 2 to 750, 3 to 500, 4 to 250, 5 to 100,or 10 to 50. The aspect ratios may, for example, be less than about1000, 750, 500, 250, 200, 150, 100, 75, 50, 25, 20, 15, 10, 9, 8, 7, 6,5, 4, 3, or 2. The aspect ratios may, for example, be greater than about1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 50, 75, or 100.

The static mixer element or reactor is generally provided with a highspecific surface area (i.e., the ratio between the internal surface areaand the volume of the static mixer element and reactor chamber). Thespecific surface area may be lower than that provided by a packed bedreactor system. The specific surface area (m² m⁻³) may be in the rangeof 100 to 40,000, 200 to 30,000, 300 to 20,000, 500 to 15,000, or 12000to 10,000. The specific surface area (m² m⁻³) may be at least 100, 200,300, 400, 500, 750, 1000, 2000, 3000, 4000, 5000, 7500, 10000, 12500,15000, 17500, or 20000. It will be appreciated that the specific surfaceareas can be measured by a number of techniques including the BETisotherm techniques.

The static mixer elements may be configured for enhancing properties,such as mixing and heat transfer, for laminar flow rates or turbulentflow rates. It will be appreciated that for Newtonian fluids flowing ina hollow pipe, the correlation of laminar and turbulent flows withReynolds number (Re) values would typically provide laminar flow rateswhere Re is <2300, transient where 2300<Re<4000, and generally turbulentwhere Re is >4000. The static mixer elements may be configured forlaminar or turbulent flow rates to provide enhanced properties selectedfrom one or more of mixing, degree of reaction, heat transfer, andpressure drop. It will be appreciated that further enhancing aparticular type of chemical reaction will require its own specificconsiderations.

In one embodiment, the static mixer element may be generally configuredfor operating at a Re of at least 0.01, 0.1, 1, 5, 50, 100, 150, 200,250, 300, 350, 400, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000,1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 3000,3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000,9500, 10000. The static mixer element may be configured for operating ina generally laminar flow Re range of about 0.1 to 2000, 1 to 1000, 10 to800, or 20 to 500. The static mixer element may be configured foroperating in a generally turbulent flow Re ranges of about 1000 to15000, 1500 to 10000, 2000 to 8000, or 2500 to 6000.

The volume displacement % of the static mixer relative to a reactorchamber for containing the mixer is in the range of 1 to 40, 2 to 35, 3to 30, 4 to 25, 5 to 20, or 10 to 15. The volume displacement % of thestatic mixer relative to a reactor chamber for containing the mixer maybe less than 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5%.

The configurations of the static mixers may be provided to enhancecross-sectional microscopic turbulence. Such turbulence may result fromvarious sources, including the geometry of CSM or the microscopicroughness of the CSM surface resulting from the 3D printing processand/or surface coating. For example, turbulent length scales may bereduced to provide better mixing. The turbulent length scales may, forexample, be in the range of microscopic length scales.

The configurations of the static mixers may be provided to enhance heattransfer properties in the reactor, for example a reduced temperaturedifferential at the exit cross-section. The heat transfer of the CSMmay, for example, provide a cross-sectional or transverse temperatureprofile that has a temperature differential of less than about 20°C./mm, 15° C./mm, 10° C./mm, 9° C./mm, 8° C./mm, 7° C./mm, 6° C./mm, 5°C./mm, 4° C./mm, 3° C./mm, 2° C./mm, or 1° C./mm.

The scaffold may be configured such that, in use, the pressure drop(i.e. pressure differential or back pressure) across the static mixers(in Pa/m) is in a range of about 0.1 to 1,000,000 Pa/m (or 1 MPa/m),including at any value or range of any values therebetween. For example,the pressure drop across the static mixer (in Pa/m) may be less thanabout 500,000, 250,000, 100,000, 50,000, 10,000, 5,000, 1,000, 750, 500,250, 100, 75, 50, 25, 20, 15, 10, or 5 Pa/m. The static mixers may beconfigured to provide a lower pressure drop relative to a specific flowrate. In this regard, the static mixers, reactor, system, and processes,as described herein, may be provided with parameters suitable forindustrial application. The above pressure drops may be maintained wherethe volumetric flow rate is at least 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5,4, 4.5, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50 ml/min.

Process for Preparing Static Mixer

A process for preparing a catalytic static mixer (CSM) element for acontinuous flow chemical reactor chamber may comprise the steps of:

providing a static mixer element comprising a scaffold defining aplurality of passages configured for mixing one or more fluidicreactants during flow and reaction thereof through the mixer; and

applying a catalytic coating to the surface of the scaffold to form acatalytic static mixer (CSM) element.

The static mixer element may be provided by additive manufacturing, suchas 3D printing. Additive manufacturing of the static mixer andsubsequent catalytic coating can provide a static mixer that isconfigured for efficient mixing, heat transfer and catalytic reaction(of reactants in continuous flow chemical reactors), and in which thestatic mixer may be physically tested for reliability and performance,and optionally further re-designed and re-configured using additivemanufacturing (e.g. 3D printing) technology. Following original designand development using additive manufacturing, the static mixer may beprepared using other manufacturing process, such as casting (e.g.investment casting). The additive manufacturing provides flexibility inpreliminary design and testing, and further re-design andre-configuration of the static mixers to facilitate development of morecommercially viable and durable static mixers.

The static mixer elements may be made by the additive manufacture (i.e.3D printing) techniques. For example, an electron beam 3D printer or alaser beam 3D printer may be used. The additive material for the 3Dprinting may be, for example, titanium alloy based powders (e.g. 45-105micrometre diameter range) or the cobalt-chrome alloy based powders(e.g. FSX-414) or stainless steel or aluminium-silicon alloy. The powderdiameters associated with the laser beam printers are typically lowerthan those used with electron beam printers.

3D printing is well understood and refers to processes that sequentiallydeposit material onto a powder bed via fusion facilitated by the heatsupplied by a beam, or by extrusion and sintering-based processes. 3Dprintable models are typically created with a computer aided design(CAD) package. Before printing a 3D model from an STL file, it istypically examined for manifold errors and corrections applied. Oncethat is done, the .STL file is processed by software called a “slicer,”which converts the model into a series of thin layers and produces aG-code file containing instructions tailored to a specific type of 3Dprinter. The 3D printing process is advantageous for use in preparingthe static mixer elements since it eliminates the restrictions toproduct design imposed by traditional manufacturing routes.Consequently, the design freedom inherited from 3D printing allows astatic mixer geometry to be further optimised for performance than itotherwise would have been.

The catalytically active scaffold may be prepared from a catalyticmaterial selected from at least one of a metal, metal alloy, cermet andmetal oxide. The process of preparing a static mixer may comprise a stepof applying a coating comprising the catalytic material onto at least asubstantial portion of the scaffold by cold spray or electrodeposition.For example, the coating may be provided on at least 50% of the surfaceof the scaffold. In other embodiments, the coating may be provided on atleast 60%, 70%, 80%, 90%, 95%, 98, or 99%, of the surface of thescaffold.

Electrodeposition or electro-plating may involve placing the scaffold ina solution containing metal salts, placing a first electrode in thesolution spaced from the scaffold, connecting a second electrode to thescaffold, and applying a voltage across the electrodes. A galvanicreaction then takes place and metal ions in the solution aggregate onthe surface of the scaffold thereby coating or plating the scaffold. Insome embodiments, an electrochemical flow cell may be used to coat thescaffold, with the scaffold acting as an anode, and the cathode beingconfigured to surround the scaffold. Electro-deposition may provide asmooth coating of catalyst material on the scaffold (as shown in FIGS.9A and 9B), and does not require line-of sight accessibility.

Cold spray coating techniques generally involve accelerating solidparticles to supersonic velocities to achieve ballistic impingement onthe surface of a substrate such that the particles adhere to and coatthe surface forming a deposition layer of material. Various metalpowders may be used for cold spraying onto a surface, and there are anumber of different types of cold spraying methods and systems includinghigh pressure cold spray, low pressure cold spray, kineticmetallisation, pulsed gas dynamic spraying, and vacuum cold spray, forexample. The particles may or may not be preheated, but the temperatureof the particles generally remains below the melting point of theparticles. The particles may be accelerated to speeds in the range of300 ms⁻¹ to 1400 ms⁻¹ and when they impinge on the surface, theparticles plastically deform and bond to the surface.

In some embodiments, the particles may be accelerated by feeding themthrough a converging-diverging nozzle with pressurised gas from a highpressure side of the nozzle to a low pressure side of the nozzle,thereby forming a supersonic gas jet with a stream of supersonic solidparticles. In some embodiments, the solid particles may be fed into thegas jet on the low pressure side of the nozzle. The nozzle may be in theform of a de Laval nozzle as shown in FIG. 3 . The gas may be heatedbefore being fed through the nozzle.

Cold spray techniques typically result in a dense layer of materialforming on the surface of the substrate. However, if the cold sprayconditions are carefully controlled a porous coating suitable forcatalysis can be formed on a suitable substrate such as a static mixerscaffold. In some embodiments, the catalytic material may be coated ontothe surface of the scaffold via a cold spraying process to form acatalytic layer. In some embodiments, the surface of the catalytic layerformed using cold spray deposition may have a high roughness (as shownin FIGS. 8A and 8B) compared with other deposition techniques such aselectro-deposition.

The increased roughness may enhance micro-scale turbulent mixing of thefluidic reactants near the surface of the catalytic layer, and mayprovide a larger surface area of catalytic material on which catalyticreactions can occur. In some applications, it may be preferable todeposit the catalytic material on the scaffold in order to form a moreporous catalytic layer, or a catalytic layer with increased roughnesscompared to that achieved using electro-deposition or other depositiontechniques.

Using an existing cold spray system or method may not be suitable forcold spraying some static mixer scaffolds, as the scaffold may bedamaged by aerodynamic forces from the impinging gas jet. Therefore, insome embodiments, a system may be put in place to mitigate or avoiddamage from the aerodynamic forces.

Referring to FIG. 6 , some embodiments relate to a system for depositinga layer of catalytic material on a scaffold to form a static mixercomprising catalytic material, the system comprising: first and secondclamps configured to hold respective ends of the scaffold to maintainthe scaffold in a tensioned state; and a cold spraying system configuredto accelerate solid particles towards the scaffold to a velocity atwhich the particles impinge on a surface of the scaffold, plasticallydeform, and bond to the surface. The first and second clamps may berotatable relative to the cold spraying system to allow the scaffold tobe coated from different relative angles by the cold spraying system.The first and second clamps may be movable relative to the cold spraysystem in a direction parallel to an axis extending from the first clampto the second clamp to allow the different parts of the scaffold to becoated by the cold spraying system. One or both of the first and secondclamps may be driven to rotate by a motor. One of the first and secondclamps may be free to rotate with the scaffold and the other clamp. Insome embodiments, one or both of the first and second clamps maycomprise or be coupled to a tensioning device to apply tension to thescaffold. Holding the scaffold in tension may reduce or mitigatevibration or bending stresses in the scaffold due to aerodynamic forcesproduced by the cold spray system as shown in FIG. 10 .

Referring to FIGS. 5 and 6 , some embodiments relate to a system fordepositing a layer of catalytic material on a scaffold to form a staticmixer comprising catalytic material, the system comprising: a coldspraying system configured to accelerate solid particles towards thescaffold to a velocity at which the particles impinge on a surface ofthe scaffold, plastically deform, and bond to the surface; and a supportmember configured to support the scaffold against aerodynamic forcesproduced by the cold spraying system. The support member may extendalong a length of the scaffold and be positioned on an opposite side ofthe scaffold to a nozzle of the cold spraying system. The support memberor jig may comprise a slit tube. The support member may comprise agenerally cylindrical tube or pipe configured to receive the scaffoldand define a window in a side wall of the tube to allow lateral line ofsight access to the scaffold for cold spraying the scaffold (as shown inFIG. 6 ). The scaffold may be rotatable relative to the support memberto allow the scaffold to be coated from different relative angles by thecold spraying system. The scaffold may be movable relative to thesupport member and/or the cold spray system in a direction parallel to alongitudinal axis of the scaffold to allow the different parts of thescaffold to be coated by the cold spraying system. Mounting the scaffoldin the support member before cold spraying the scaffold may reduce ormitigate vibration or bending stresses in the scaffold due toaerodynamic forces produced by the cold spray system.

In some embodiments, the scaffold may be held in the chuck of a latheand the cold spray nozzle may be moved in a direction parallel to thelongitudinal axis of the scaffold to make one or more passes along thescaffold to coat different parts of the scaffold as shown in FIG. 7 .The support member may be held in the chuck with the scaffold, or thesupport member may be held in the cuck and the scaffold held in thesupport member. The scaffold may be rotated between successive rounds ofcold spraying to present different aspects of the surface of thescaffold to the cold spray nozzle.

In some embodiments, the support member may be held stationary relativeto a body of the lathe, and the scaffold held in the chuck so that thelathe can rotate the scaffold relative to the support member to coat thesurface of the scaffold from different angles. In some embodiments, thescaffold may not directly contact the scaffold, or may only contact partof the scaffold, but may none-the-less reduce or mitigate theaerodynamic forces that the scaffold is subjected to during the coldspraying process.

Some embodiments relate to a method for depositing a layer of catalyticmaterial on a scaffold to form a static mixer comprising catalyticmaterial, the method comprising: using a cold spraying system comprisinga cold spraying nozzle to accelerate solid particles towards thescaffold to a velocity at which the particles impinge on a surface ofthe scaffold, plastically deform, and bond to the surface, wherein thescaffold is supported by a support member to reduce or mitigate effectsof aerodynamic forces produced by the cold spraying system on thescaffold; moving the cold spraying nozzle in a direction parallel to alongitudinal axis of the scaffold to make one or more cold sprayingpasses of the scaffold thereby coating different portions of thescaffold along a length of the scaffold; and rotating the scaffoldrelative to the cold spraying nozzle to coat scaffold from differentangular directions.

Some embodiments relate to a method of forming a catalytic static mixer,the method comprising: coating a scaffold with a catalytic materialusing a cold spraying process. In some embodiments, the method may firstcomprise forming the scaffold using an additive manufacturing process,such as 3D printing.

Catalyst Material

Catalytically reactive sites of the scaffold may be provided by at leastone of the following: the scaffold being formed from a catalyticmaterial; a catalyst material being intercalated, interspersed and/orembedded with at least part of the scaffold; and at least a part of thesurface of the scaffold comprising a coating comprising a catalystmaterial. In one embodiment, the catalytically reactive sites areprovided by a coating comprising a catalyst material on the scaffold.

It will be appreciated that the catalyst material may be selected andvaried based on a particular reaction or application required. Thecatalyst material may be selected to provide for heterogeneous catalysisreactions in a continuous flow reactor environment. A wide range ofheterogeneous catalysis chemical reactions may be provided for byselection from a wide range of catalytic materials, including but notlimited to the following: hydrogenations using hydrogen gas, transferhydrogenations using a liquid hydrogen donor, catalytic oxidations,reductive aminations, carbon-carbon couplings including Suzuki,Sonogashira, Heck, Stille, Negishi, Ullmann, Kumada couplings and othermetal catalysed organic transformations.

Hydrogenation Reactions

The hydrogenations using hydrogen gas or transfer hydrogenations using aliquid hydrogen donor may be for hydrogenating compounds containing oneor more functional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, ketones, carboxylic acids, ethers, esters,halides, imines, amides, nitrogen, nitriles and nitro groups.

In an embodiment, the functional groups selected from one or more ofalkenes, alkynes, aldehydes, carbonyls, ketones, carboxylic acids,ethers, esters, halides, imines, amides, nitrogen, nitriles and nitrogroups may be hydrogenated as follows: alkenes to alkanes, alkynes toalkenes and/or alkanes, aldehydes to alcohols, carbonyls to alcohols,ketones to alcohols, carboxylic acids to alcohols, ethers to alcohols,esters to alcohols, halides to hydrogen, imines to amines, amides toamines and alcohols, nitrogen to ammonia, nitriles to amines, and nitrogroups to hydrogen, amine and/or analines.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more alkene functional groups. For example, compoundscontaining one or more alkene functional group include compoundspreferably comprising from one to about 20 carbon atoms and one or morealkene group, and may include monoolefins and diolefins. Typicalmonoolefins include, but are not limited to, ethylene, propylene,1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, methyl-1-butenes(such as 2-methyl-1-butene), methyl-2-butenes (such as2-methyl-2-butene), 1-hexene, 2-hexene, 3-hexene, methyl-1-pentenes,2,3-dimethyl-1-butene, 1-heptene, 2-heptene, 3-heptene,methyl-1-hexenes, methyl-2-hexenes, methyl-3-hexenes, dimethylpentenes,ethylpentenes, octenes, methylheptenes, dimethyl-hexenes, ethylhexenes,nonenes, methyloctenes, dimethylheptenes, ethylheptenes,trimethylhexenes, cyclopentene, cyclohexene, methylcyclopentene,cycloheptene, methylcyclohexene, dimethylcyclopentenes,ethylcyclopentenes, cyclooctenes, methylcycloheptenes,dimethylcyclohexenes, ethylcyclohexenes, trimethylcyclohexenes,methylcyclooctenes, dimethylcyclooctenes, ethylcyclooctenes, andcombinations and isomers thereof. The monoolefin compounds may behydrogenated to their corresponding alkane compound containing the samenumber of carbons atoms per molecule as the monoolefin compound.

Typical diolefins include, but are not limited to, propadiene,1,2-butadiene, 1,3-butadiene, isoprene, 1,2-pentadiene, 1,3-pentadiene,1,4-pentadiene, 1,2-hexadiene, 1,3-hexadiene, 1,4-hexadiene,1,5-hexadiene, 2-methyl-1,2-pentadiene, 2,3-dimethyl-1,3-butadiene,heptadienes, methylhexadienes, octadienes, methylheptadienes,dimethylhexadienes, ethylhexadienes, trimethylpentadienes,methyloctadienes, dimethylheptadienes, ethyloctadienes,trimethylhexadienes, nonadienes, decadienes, undecadienes, dodecadienes,cyclopentadienes, cyclohexadienes, methylcyclopentadienes,cycloheptadienes, methylcyclohexadienes, dimethylcyclopentadienes,ethylcyclopentadienes, dicyclopentadiene and combinations and isomersthereof. The diolefin compounds may be hydrogenated to the correspondingmonoolefins containing the same number of carbon atoms per molecule asthe diolefin molecule. For example, propadiene is hydrogenated topropylene; 1,2-butadiene and 1,3-butadiene are hydrogenated to 1-buteneand 2-butene; 1,3-pentadiene and 1,4-pentadiene are hydrogenated to1-pentene and 2-pentene; isoprene is hydrogenated to methyl-1-pentenesand methyl-2-pentenes; and 1,3-cyclopentadiene is hydrogenated tocyclopentene. Alternatively, the diolefin compounds may be hydrogenatedfurther to the corresponding alkane compound containing the same numberof carbon atoms per molecule as the diolefin compound. For example,propadiene is hydrogenated to propane; 1,2-butadiene and 1,3-butadieneare hydrogenated to butane; 1,3-pentadiene and 1,4-pentadiene arehydrogenated to pentane.

The alkene containing compounds may also contain other functional groupsselected from one or more of, alkynes, aldehydes, carbonyls, ketones,carboxylic acids, ethers, esters, halides, imines, amides, nitrogen,nitriles and nitro groups. Typical compounds include, but are notlimited to, vinyl acetate, oleic acid, or cinnamaldehyde.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more alkyne functional group. For example, compoundscontaining one or more alkyne functional group include compoundspreferably comprising from 1 to about 20 carbon atoms and one or morealkyne group. Typical alkynes include, but are not limited to,acetylene, propyne (also referred to as methylacetylene), 1-butyne,2-butyne, 1-pentyne, 2-pentyne, 3-methyl-1-butyne, 1-hexyne, 1-heptyne,1-octyne, 1-nonyne, 1-decyne and combinations and isomers thereof. Thealkynes may be hydrogenated to the corresponding alkenes. For example,acetylene is hydrogenated to ethylene; propyne is hydrogenated topropylene; and the butynes are hydrogenated to the corresponding butenes(e.g., 1-butene, 2-butenes). Alternatively, the alkyne compounds may behydrogenated to the corresponding alkane compound containing the samenumber of carbon atoms per molecule as the alkyne molecule. For example,acetylene is hydrogenated to ethane, propyne is hydrogenated to propane,and the butynes are hydrogenated to butane. The alkyne containingcompounds may also contain other functional groups selected from one ormore of, alkenes, aldehydes, carbonyls, ketones, carboxylic acids,ethers, esters, halides, imines, amides, nitrogen, nitriles and nitrogroups. Typical compounds include, but are not limited to, vinylacetate, oleic acid, or cinnamaldehyde.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more aldehyde functional groups. For example,compounds containing one or more aldehyde functional groups includecompounds preferably comprising from 1 to about 20 carbon atoms and oneor more aldehyde groups. Typical aldehydes include, but are not limitedto, formaldehyde, acetaldehyde, propionaldehyde, n- andiso-butyraldehydes, n- and iso-valeraldehyde, n-hexaldehyde,n-heptaldehyde, n-octanal, 2-ethylhexanal, 2-ethylhex-2-enal (2-ethylpropyl acrolein), n-decanal, 2-ethylbutanal, propargyl aldehyde,acrolein, glyoxal, crotonaldehyde, furfural, aldol,hexahydrobenzaldehyde, alpha-citronellal, citral, chloral,trimethylacetaldehyde, diethylacetaldehyde, tetrahydrofurfural,phenylacetaldehyde, cinnamaldehyde, hydrocinnamaldehyde, as well ascombinations and isomers thereof. The aldehyde compounds may behydrogenated to the corresponding alcohol compound containing the samenumber of carbon atoms per molecule as the aldehyde molecule. Forexample, formaldehyde is hydrogenated to methanol, acetaldehyde ishydrogenated to ethanol, propionaldehyde is hydrogenated to propanol.The aldehyde containing compounds may also contain other functionalgroups selected from one or more of, alkenes, alkynes, carbonyls,ketones, carboxylic acids, ethers, esters, halides, imines, amides,nitrogen, nitriles and nitro groups. Typical compounds include, but arenot limited to, vinyl acetate, oleic acid, or cinnamaldehyde.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more carbonyl functional groups. For example,compounds containing one or more carbonyl functional groups includecompounds preferably comprising from 1 to about 20 carbon atoms and 1 ormore carbonyl groups. Typical compounds containing carbonyl functionalgroups may also characterise other compounds containing other types offunctional groups including aldehydes, carbonyls, ketones, carboxylicacids, esters, amides, enones and imide groups. The compounds containingcarbonyl functional groups may be hydrogenated to the correspondingalcohol compound containing the same number of carbon atoms permolecule. The carbonyl containing compounds may also contain otherfunctional groups selected from one or more of, alkenes, alkynes,aldehydes, ketones, carboxylic acids, ethers, esters, halides, imines,amides, nitrogen, nitriles and nitro groups. Typical compounds include,but are not limited to, vinyl acetate, oleic acid, or cinnamaldehyde.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more carboxylic acid functional groups. For example,compounds containing one or more carboxylic acrid functional groupsinclude compounds preferably comprising from 1 to about 20 carbon atomsand 1 or more carbonyl groups. Typical carboxylic acid containingcompounds include, but are not limited to, acetic acid, oxalic acid,propanoic acid, butanoic acid, pentanoic acid, hexanoic acid heptanoicacid, octanoic acid, nonanoic acid, decanoic acid, undecoanoic acid,dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoicacid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid,nonadecanoic acid, and eicosanoic acid, and isomers thereof. Thecompounds containing carboxylic acid functional groups may behydrogenated to the corresponding alcohol compound containing the samenumber of carbon atoms per molecule. The carboxylic acid containingcompounds may also contain other functional groups selected from one ormore of alkenes, alkynes, aldehydes, carbonyls, ketones, ethers, esters,halides, imines, amides, nitrogen, nitriles and nitro groups. Typicalcompounds include, but are not limited to, vinyl acetate, oleic acid, orcinnamaldehyde.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more ether functional groups. For example, compoundscontaining one or more ether functional groups include compoundspreferably comprising from 1 to about 20 carbon atoms and 1 or moreether groups. Typical ethers include, but are not limited to, diethylether, di-tert-butyl ether, glycol ethers, tetrahydrofuran, diisopropylether, dimethoxyethane. The compounds containing ether functional groupsmay be hydrogenated to both an alcohol containing compound. The ethercontaining compounds may also contain other functional groups selectedfrom one or more of alkenes, alkynes, aldehydes, carbonyls, carboxylicacids, ketones, esters, halides, imines, amides, nitrogen, nitriles andnitro groups.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more ester functional groups. For example, compoundscontaining one or more ester functional groups include compoundspreferably comprising from 1 to about 20 carbon atoms and 1 or moreester groups. The ester containing compounds may also contain otherfunctional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, carboxylic acids, ketones, ethers, halides,imines, amides, nitrogen, nitriles and nitro groups.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more imine functional groups. For example, compoundscontaining one or more imine functional groups include compoundspreferably comprising from 1 to about 20 carbon atoms and 1 or moreimine groups. The imine containing compounds may also contain otherfunctional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, carboxylic acids, ketones, ether, esters, halides,amides, nitrogen, nitriles and nitro groups.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more amide functional groups. For example, compoundscontaining one or more amide functional groups include compoundspreferably comprising from 1 to about 20 carbon atoms and 1 or moreamide groups. The amide containing compounds may also contain otherfunctional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, carboxylic acids, ketones, ethers, esters,halides, imines, nitrogen, nitriles and nitro groups.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more nitrogen functional groups. For example,compounds containing one or more nitrogen functional groups includecompounds preferably comprising from 1 to about 20 carbon atoms and 1 ormore nitrogen groups. The nitrogen containing compounds may also containother functional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, carboxylic acids, ketones, ethers, esters,halides, imines, amides, nitriles and nitro groups.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more nitrile functional groups. For example, compoundscontaining one or more nitrile functional groups include compoundspreferably comprising from 1 to about 20 carbon atoms and 1 or morenitrile groups. The nitrile containing compounds may also contain otherfunctional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, carboxylic acids, ketones, ethers, esters,halides, imines, amides, nitrogen, and nitro groups.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more nitro functional groups. For example, compoundscontaining one or more nitro functional groups include compoundspreferably comprising from 1 to about 20 carbon atoms and 1 or morenitro groups. The nitro containing compounds may also contain otherfunctional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, carboxylic acids, ketones, ethers, esters,halides, imines, amides, nitrogen, and nitriles.

In an embodiment, the hydrogenation may be for hydrogenating compoundscontaining one or more halide functional groups. Such hydrogenation isalso known has halide reduction. For example, compounds containing oneor more halide functional groups include compounds preferably comprisingfrom 1 to about 20 carbon atoms and 1 or more halide groups. The halidefunctional groups in the compounds containing one or more halidefunctional groups are selected from the group consisting of fluoride(F⁻), chloride (Cl⁻), bromide (Br⁻), iodide (I⁻) and astatide (At⁻). Thehailde containing compounds may also contain other functional groupsselected from one or more of alkenes, alkynes, aldehydes, carbonyls,carboxylic acids, ketones, ethers, esters, imines, amides, nitrogen,nitriles and nitro groups. For example, typical compounds containing oneor more halide functional groups include, but are not limited to,organohalides (e.g. acid halides).

In an embodiment, the hydrogenation may also be for hydrogenatingcompounds to remove various protecting groups comprising any one or moreof the above mentioned functional groups, such as protected ethers (e.g.benzyl or silyl protected ethers, see Green et al, Protective Groups inOrganic Synthesis, Wiley-Interscience, New York, 1999).

The temperature (° C.) for the hydrogenation of compounds containing oneor more functional groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, ketones, carboxylic acids, ethers, esters, imines,amides, nitrogen, nitriles and nitro groups may be in the range of about10 to 200, 20 to 195, 40 to 190, 60 to 185, 80 to 180, 100 to 175, 120to 170, 140 to 165. For example, the temperature (° C.) may be at leastabout 20, 40, 60, 80, 100, 120, 140, 160, 180, or 200. For example, thetemperature (° C.) may be less than about 200, 190, 180, 170, 160, 150,140, 100 or 50. The temperature may also be provided at about any ofthese values or in a range between any of these values, such as a rangebetween about 20 to 200° C., about 50 to 180° C., or about 100 to 150°C.

The pressure (bar) for the hydrogenation of compounds containing on oremore function groups selected from one or more of alkenes, alkynes,aldehydes, carbonyls, ketones, carboxylic acids, ethers, esters,halides, imines, amides, nitrogen, nitriles and nitro groups may be inthe range of about 1 to 50, 5 to 40, 10 to 30 or 15 to 20. For example,the pressure (bar) may be at least about 1, 5, 10, 15, 20, 25, 30, 35,40, 45 or 50. For example, the pressure (bar) may be less than about 50,40, 30, 20, 15, 10 or 5. For example, the pressure (bar) may be about16. The pressure (bar) may also be provided at about any of these valuesor in a range between any of these values, such as a range between about5 to 50 or about 10 to 25.

The scaffold of the static mixer may comprise or consist of at least oneof a metal, metal alloy, cermet and metal oxide. The scaffold may be ametal scaffold, for example formed from metals or metal alloys. Thescaffold may be formed from a metal or metal alloy capable of catalyticreactions, such as palladium. The metal scaffold may be prepared from amaterial suitable for additive manufacturing (i.e. 3D printing). Themetal scaffold may be prepared from a material suitable for furthersurface modification to provide or enhance catalytic reactivity, forexample a metal including nickel, titanium, palladium, platinum, gold,copper, aluminium or their alloys and others, including metal alloyssuch as stainless steel. In one embodiment the metal for the scaffoldmay comprise or consist of titanium, stainless steel, and an alloy ofcobalt and chromium. In another embodiment, the metal for the scaffoldmay comprise or consist of stainless steel and cobalt chromium alloy.Using additive manufacturing techniques, i.e. 3D metal printing, themetal scaffold can be specifically designed to perform two major tasks:a) to act as a catalytic layer or a substrate for a catalytic layer, b)to act as a flow guide for optimal mixing performance during thechemical reaction and subsequently assist transfer of exothermic heat tothe walls of the reactor tube (single phase liquid stream or multiphasestream) inside the reactor.

The scaffold or catalytic material may comprise or consist of a metalselected from at least one of iron, aluminium, cobalt, copper, zinc,nickel, palladium, platinum, gold, silver, ruthenium, iridium, rhodium,titanium vanadium, zirconium, niobium, tantalum, and chromium, or ametal alloy, cermet or metal oxide thereof. The scaffold or catalyticmaterial may comprise or consist of titanium, aluminium, nickel, iron,silver, cobalt, chromium, or an alloy thereof. The scaffold may compriseor consist of titanium, titanium alloy or stainless steel. The titaniumalloy may comprise aluminium and vanadium, for example. Non-limitingexamples of other transition metals that may be used in metal alloys arezirconium, niobium and tantalum.

In an embodiment, the scaffold or catalytic material comprises at leastone of a metal, semi-metal and metal oxide. For example, the scaffold orcatalytic material may comprise one or more of the following:

a metal selected from iron, cobalt, chromium, aluminium, vanadium,copper, zinc, nickel, palladium, platinum, gold, silver, ruthenium,iridium, and rhodium, or alloys or mixtures thereof;

a semimetal selected from Bi, CdTe, HgCdTe, GaAs, or mixtures thereofand

a metal oxide selected from PbO, PbO₂, ZnO, TiO₂, CoO, Al₂O₃, ormixtures thereof.

The surface of the scaffold may be modified to provide or enhancecatalytic reactivity, such as by roughening, and/or depositing a metalor alloy on at least a part of the surface of the scaffold, such as afurther deposited (sputtered) layer. Surface roughening may be achievedby any process of acid treatment, heat treatment in controlled gasatmospheres, physical vapour deposition, cold spray, plasma spray, ionimplantation flame spray pyrolysis electrodeposition, chemical vapourdeposition, glow discharge, sputtering, and plating or by any mechanicalmeans. The surface modification may provide one or more outer layers,for example one or more metal deposited (e.g. sputtered) layers.

A catalytic material may refer to a catalyst by itself or to a materialor composition comprising a catalyst. The catalytic material may beprovided in a composition with one or more additives, such as binders,to facilitate coating of the catalyst to the scaffold. The catalyst orcoating thereof may be provided as a partial coating or a complete layeron the scaffold. The coating or layer of the catalyst on the scaffoldmay be provided in one or more layers. The catalyst may be deposited onthe scaffold by brush coating, painting, slurry spraying, spraypyrolysis, sputtering, chemical or physical vapour depositiontechniques, electroplating, screen printing, tape casting,electro-deposition, flame spraying, arc spraying, plasma spraying,detonation spraying, high velocity oxy-fuel flame spraying, laserspraying, or cold spraying. A catalytic material or coating of thescaffold may be provided by a metal deposition process, for example anelectrodeposition or cold spray coating. Electroplating and cold spraycoating techniques have been surprisingly shown to provide furtheradvantages for the catalytic static mixers. The electroplating and coldspray techniques can provide a single step process in forming a porouscatalytic coating. Standard catalyst coating techniques have typicallyinvolved a two-step process of first forming a porous metal oxide layerand then secondly impregnating the catalyst into the pre-formed porouslayer. In an embodiment, the catalytic material or coating on thescaffold does not comprise a metal oxide porous layer as a support forimpregnated catalytic material.

It will be appreciated that the catalytic material, or composition orcoating thereof, may include one or more additives. The additives mayinclude catalysts or promoters to enhance reaction rates at the scaffoldor static mixer surface. The one or more additives may be incorporatedwithin the scaffold itself (such as by doping), for example by additionto additive manufacturing material. Promoters may include materials witha low electronegativity. Suitable promoters may be selected from alkalimetals (K, Cs) and alkali earths (mostly Ba). It will be appreciatedthat exceptions may include the rare earths (La, Ce and Sm) that have amoderately high electronegativity.

The catalyst material may include a dissociation catalyst, which may bechosen from the group consisting of molybdenum, tungsten, iron,ruthenium, cobalt, boron, chromium, tantalum, nickel, and alloys,compounds and mixtures thereof.

In one embodiment, the scaffold is a metal scaffold comprising a coatingcomprising catalytic material. In another embodiment, the metal scaffoldcomprises titanium, nickel, aluminium, stainless steel, cobalt,chromium, any alloy thereof, or any combination thereof. In anotherembodiment, the metal scaffold comprises at least one of a stainlesssteel and aluminium. In another embodiment, the metal scaffold comprisestitanium, or a titanium alloy. In a further embodiment, the catalyticmaterial comprises nickel. Further advantages may be provided whereinthe metal scaffold comprises or consists of stainless steel or a cobaltchromium alloy.

In one embodiment, the catalytically active scaffold is a stainlesssteel scaffold or a cobalt chromium alloy scaffold, and the surface ofthe scaffold is provided with an electrodeposition or cold spray coatingcomprising a metal selected from platinum or nickel.

The weight % of the coating or catalyst material, based on total weightof catalytic static mixer, may be in the range of 1 to 40%, 2 to 35%, 5to 30%, 10 to 25%, or 15 to 20%. The weight % of the coating comprisingthe catalyst material, based on total weight of catalytic static mixer,may be at least 1%, 5%, 10%, 15%, 20%, 35%, 30%, 35%, or 40%. The weight% of the coating comprising the catalyst material, based on total weightof catalytic static mixer, may be less than 50%, 40%, 30%, 20%, 15%,10%, 5%, or 3%.

Continuous Flow Systems and Reactors

The present disclosure provides a continuous flow chemical reactor foruse in catalytic reactions of one or more fluidic reactants. The reactormay comprise one or more chamber sections in fluid communication witheach other. It will be appreciated that at least one chamber sectioncomprises a static mixer element. The chamber sections may be referredto as chamber modules, wherein each module may contain one or morestatic mixer elements. The static mixer element can be configured forinserting into a continuous flow chemical reactor, which may be referredto as a “static mixer insert”. The static mixer elements or inserts mayalso be provided in the form of one or more modules. It will beappreciated that the static mixer is an integral part of the chemicalreactor. The static mixer and chamber section together form the reactorchamber, which may be provided as a single unit. The chamber section mayprovide the housing for the static mixer. The chamber section mayoptionally include a heat exchanger system, which may be used forcontrolling heat removed from the reactor chamber during its operation.The one or more static mixer elements or chamber sections may beconfigured for use in series or parallel operation. It will beappreciated that the static mixer, or reactor thereof, may comprise oneor more reactant inlets for supply of one or more fluidic reactants to achamber section, and one or more outlets in fluid communication with thestatic mixer for receiving an output stream comprising a product orproducts of the reaction.

In one embodiment, the continuous flow chemical reactor is a tubular orplug flow reactor.

In another embodiment, the reactor comprises a heat exchanger forcontrolling the temperature of the reactor, chamber section, catalyticstatic mixer, or fluidic components thereof. The heat exchanger may be ashell and tube heat exchanger design or configuration.

In an embodiment, the aspect ratios of the reactor may, for example, besimilar to those previously described for the static mixer such that astatic mixer element may be configured for insertion into the reactor.

The present disclosure also provides a system for a continuous flowchemical reaction process comprising:

a continuous flow chemical reactor comprising one or more static mixersaccording to any of the embodiments described herein;

a pump for providing fluidic flow for one or more fluidic reactants andany products thereof through the reactor;

optionally one or more heat exchangers for controlling the temperatureof the reactor, chamber section, catalytic static mixer, or fluidiccomponents thereof; and

a control means for controlling one or more of the parameters of thesystem selected from concentration, flow rate, temperature, pressure,and residence time, of the one or more fluidic reactants, sources offluidic reactants, carrier fluids, or products of the reaction.

The system may further comprise a dispersing unit, which can beconfigured before and/or after the chamber section. The dispersing unitmay comprise a static mixer for dispersing the one or more fluidicreactants.

The system may further comprise a spectrometer, which can be used foridentifying and determining concentrations for any one or more fluidicreactants or products thereof.

One or more of the reactor, reactor chamber, chamber section and staticmixer, may each be provided in modular form for complimentaryassociation thereof. The system may comprise a plurality of reactors,which may be of similar or different internal and/or externalconfiguration. The reactors may operate in series or in parallel. Itwill be appreciated that the system, reactor, or each chamber section,may include one or more inlets and outlets to provide supply ofreactants, obtain products, or to recirculate various reactants and/orproducts.

It will also be appreciated that the reactor or system may be designedfor recycling of the various reactants, reactant sources, intermediaryproducts, or desired products provided to and produced in the chambersections. The reactor or system may be provided in various designs andforms, for example in the form of a tubular reactor. In anotherembodiment, the reactor is a single pass reactor.

The system and processes may also be integrated into more complexsystems, such as systems and processes comprising a coal gasifier,electrolyser and/or natural gas reformer etc.

Catalytic Processes and Reactions

The static mixer is for use in a continuous flow chemical reactionsystem and process. The process may be an in-line continuous flowprocess. The in-line continuous flow process may be a recycle loop or asingle pass process. In one embodiment, the in-line continuous flowprocess is a single pass process.

As mentioned above, the chemical reactor comprising the static mixerelement is capable of performing heterogeneous catalysis reactions in acontinuous fashion. The chemical reactor may use single or multi-phasefeed and product streams. In one embodiment, the substrate feed(comprising one or more reactants) may be provided as a continuousfluidic stream, for example a liquid stream containing either: a) thesubstrate as a solute within an appropriate solvent, or b) a liquidsubstrate, with or without a co-solvent. It will be appreciated that thefluidic stream may be provided by one or more gaseous streams, forexample a hydrogen gas or source thereof. The substrate feed is pumpedinto the reactor using pressure driven flow, e.g. by means of a pistonpump.

The present disclosure also provides a process for synthesizing aproduct by catalytic reaction of one or more fluidic reactants, theprocess comprising the steps of:

providing a continuous flow chemical reactor comprising a static mixerelement or system according to any of the embodiments described herein;

providing at least a first fluidic reactant to the reactor via the oneor more reactant inlets;

operating the chemical reactor, or control means thereof, to provideflow and catalytic reaction of the at least first fluidic reactantthrough the catalytic static mixer; and

obtaining an output stream comprising a product of a catalytic reactionof the at least first reactant.

The process may be for synthesizing a product by heterogeneous catalyticreaction of at least a first fluidic reactant with a second fluidicreactant, which may comprise:

providing a continuous flow chemical reactor comprising a static mixerelement or system according to any of the embodiments described herein;

providing at least a first and second fluidic reactants, or sourcethereof, to the reactor via the one or more reactant inlets;

operating the chemical reactor, or control means thereof, to provideflow and catalytic reaction of the first and second fluidic reactantthrough the static mixer; and

obtaining an output stream comprising a product of a catalytic reactionof at least the first and second fluidic reactants.

It will be appreciated that various parameters and conditions used inthe process, such as temperatures, pressures and concentration/amountsof materials and reactants, may be selected depending on a range ofvariables of the process including the product to be synthesised,chemical reaction or mechanisms involved, reactant source, selection ofcatalyst(s) used, or type of reactor being used and materials andconfiguration thereof. For example, differences will exist where the oneor more fluidic reactants, or co-solvents (e.g. inert carriers) etc.,are gases, liquids, solids, or combinations thereof. For example, one ormore fluidic reactants may be provided in a fluidic carrier, such as asolute reactant in liquid carrier or particularised reactant in acarrier gas. The one or more fluidic reactants may be provided as a gas,for example a gas comprising molecular hydrogen or a source of hydrogen.

Temperatures (° C.) in relation to the process may be in a range between−50 and 400, or at any integer or range of any integers there between.For example, the temperature (° C.) may be at least about −50, −25, 0,25, 50, 75, 100, 150, 200, 250, 300, or 350. For example, thetemperature (° C.) may be less than about 350, 300, 250, 200, 150, 100,or 50. The temperature may also be provided at about any of these valuesor in a range between any of these values, such as a range between about0 to 250° C., about 25 to 200° C., or about 50 to 150° C.

As previously mentioned with respect to the static mixer element, theprocess may involve operation at a Re of at least about 0.01, 0.1, 1, 5,50, 100, 150, 200, 250, 300, 350, 400, 550, 600, 650, 700, 750, 800,850, 900, 950, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800,1900, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000,7500, 8000, 8500, 9000, 9500, or 10000. The process may involveoperation at a Re range provided by any two of the previously recitedvalues. The process may involve operation at a generally laminar flow,for example a Re range of about 50 to 2000, 100 to 1500, 150 to 1000, or200 to 800. The process may involve operation at a generally turbulentflow, for example at a Re range of about 3000 to 15000, 4000 to 10000,or 5000 to 9000.

The volume displacement % of the static mixer relative to a reactorchamber for containing the mixer is in the range of 1 to 40, 2 to 35, 3to 30, 4 to 25, 5 to 20, or 10 to 15. The volume displacement % of thestatic mixer relative to a reactor chamber for containing the mixer maybe less than 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5%.

The configurations of the static mixers may be provided to enhancecross-sectional microscopic turbulence. Such turbulence may result fromvarious sources, including the geometry of CSM or the microscopicroughness of the CSM surface resulting from the 3D printing process. Forexample, turbulent length scales may be reduced to provide bettermixing. The turbulent length scales may, for example, be in themicroscopic length scales.

The configurations of the static mixers may be provided to enhance heattransfer properties in the reactor, for example a reduced temperaturedifferential at the exit cross-section. The heat transfer of the CSMmay, for example, provide a cross-sectional or transverse temperatureprofile that has a temperature differential of less than about 20°C./mm, 15° C./mm, 10° C./mm, 9° C./mm, 8° C./mm, 7° C./mm, 6° C./mm, 5°C./mm, 4° C./mm, 3° C./mm, 2° C./mm, or 1° C./mm.

The scaffold may be configured such that, in use, the pressure drop (orback pressure) across the static mixers (in Pa/m) is in a range of about0.1 to 1,000,000 Pa/m (or 1 MPa/m), including at any value or range ofany values therebetween. For example, the pressure drop (or backpressure) across the static mixer (in Pa/m) may be less than about500,000, 250,000, 100,000, 50,000, 10,000, 5,000, 1,000, 750, 500, 250,100, 75, 50, 25, 20, 15, 10, or 5 Pa/m. The static mixers may beconfigured to provide a lower pressure drop relative to a specific flowrate. In this regard, the static mixers, reactor, system, and processes,as described herein, may be provided with parameters suitable forindustrial application. The above pressure drops may be maintained wherethe volumetric flow rate is at least 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5,4, 4.5, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 500, 1000 ml/min.

The process may involve a mean residence time in the static mixer orreactor in a range of about 1 second to about 5 hours. The meanresidence time (in minutes) may, for example, be less than about 300,250, 200, 150, 120, 100, 80, 60, 45, 30, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2,1, 0.5 or 0.1. The mean residence time (in minutes) may, for example, begreater than about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 30, 45,60, 80, 100, 120, 150, 200, or 250. The mean residence time may beprovided as a range selected from any two of these previously mentionedvalues. For example, the mean residence time may be in a range of 2 to10, 3 to 8, 4 to 7, or 5 to 6 minutes.

The process may provide a product conversion rate (% reactant convertedto product) of at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60,65, 70, 75, 80, 85, 90, 95, 98, or 99%.

The process may involve a heterogeneous catalytic reaction selected fromhydrogenations, oxidations, carbon-carbon couplings, and reductiveaminations. In one embodiment, the heterogeneous catalytic reaction is ahydrogenation reaction. It will be appreciated that hydrogenationreactions will involve at least a first fluidic reactant being hydrogenand a second reactant being an organic compound capable ofhydrogenation. The hydrogen source may be hydrogen gas (molecularhydrogen) or a liquid hydrogen donor. A pre-step for hydrogenation maybe introducing hydrogen gas for pre-activation, for example at a lowerflow rate before introducing an organic compound capable ofhydrogenation.

For heterogeneous reactions involving mixtures of gases and liquids, thegas:liquid ratio (volume/volume) may be at least 1:1, 2:1, 3:1, 4:1,5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, or 15:1. Thegas:liquid ratio (volume/volume) may be less than 15:1, 14:1, 13:1,12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, or 2:1. Thegas:liquid ratio (volume/volume) may be provided as a range selectedfrom any two of these previously mentioned values. For example, thegas:liquid ratio may be in a range of 2:1 to 6:1.

The catalyst or catalyst material on the static mixer may require achemical or physical (heating) pre-activation process step, for examplefor hydrogenations pre-activating by exposure of the catalyst materialto molecular hydrogen or a source of hydrogen. In one embodiment, thecatalyst material on the scaffold is pre-activated, for example bycontacting with an activating fluid (e.g. hydrogen gas) for at least 1,2, 5, 10, 15, 20, 25 or 30 minutes. The pre-activation may occur forless than 30, 25, 20, 15, 10, 5, 2, or 1 minutes. The pre-activation mayoccur for less than 30, 25, 20, 15, 10, 5, 2, or 1 minute. Thepre-activation may occur between a range of any two of the above timevalues.

The catalytic reactions may be hydrogen insertion reactions that involvethe use of hydrogenation catalysts. A hydrogen insertion orhydrogenation catalyst facilitate the insertion of hydrogen intointramolecular bonds of a reactant, e.g., a carbon-oxygen bond to formthe oxygen containing organic materials described above, conversion ofunsaturated bonds to saturated bonds, removal of protection groups suchas converting O-benzyl groups to hydroxyl groups, or reaction of anitrogen triple bond to form ammonia or hydrazine or mixtures thereof.The hydrogen insertion or hydrogenation catalyst may be chosen from thegroup consisting of cobalt, ruthenium, osmium, nickel, palladium,platinum, and alloys, compounds and mixtures thereof. In an embodiment,the hydrogen insertion or hydrogenation catalyst comprises or consistsof platinum or titanium. In ammonia synthesis the catalyst mayfacilitate the dissociative adsorption of a hydrogen species source anda nitrogen species source for subsequent reaction. In a furtherembodiment, the hydrogen insertion or hydrogenation catalyst is coatedusing electro-deposition or cold spray.

Design Process

The design process may comprise any of the embodiments previouslydescribed herein relating to the process for preparing the catalyticstatic mixer (CSM) element comprising additive manufacturing, such as 3Dprinting. The additive manufacturing provides flexibility in preliminarydesign and testing, and further re-design and re-configuration of thestatic mixers to facilitate development of more commercially viablestatic mixers.

A process for design and manufacture of a catalytic static mixer (CSM)element for a continuous flow chemical reactor chamber may comprise thesteps of:

designing a prototype static mixer element comprising a scaffolddefining a plurality of passages configured for mixing one or morefluidic reactants during flow and reaction thereof through the mixer;

additive manufacturing the prototype static mixer element; applying acatalytic coating to the surface of the scaffold of the prototype staticmixer element to form a prototype catalytic static mixer (CSM) element;

testing the prototype CSM for at least one of suitability for catalyticcoating or operational performance and durability in a continuous flowchemical reactor;

redesigning the static mixer element to enhance at least one ofsuitability for catalytic coating or operational performance anddurability in a continuous flow chemical reactor; and

manufacturing the redesigned static mixer element comprising aredesigned scaffold defining a plurality of passages configured formixing one or more fluidic reactants during flow and reaction thereofthrough the mixer, and applying a catalytic coating to the surface ofthe scaffold to form the catalytic static mixer (CSM) element.

The process for preparing the catalytic static mixer (CSM) element maybe a process for the design of at least one of performance, durabilityand manufacturability of the CSM. The step of applying the catalyticcoating to the surface of the scaffold may comprise or consist ofelectrodeposition or cold spray. The scaffold and catalytic coating maybe provided by any embodiments thereof as described herein. Themanufacturing of the re-designed static mixer element may be by variousmethods known in the art, for example casting (e.g. investment casting)or additive manufacture. The step of testing the CSM, re-designing thestatic mixer element and manufacturing the CSM may be repeated one ormore times to further enhance at least one of performance, durability,manufacturability, or scaffold suitability for catalytic coating.

Computational fluid dynamics (CFD) software can be used in the design(or re-design) to obtain various enhanced configurations of the CSMs andscaffolds, which will by determined by the desired applications andassociated catalytic reactions. For example, a design process can beused to develop configurations and geometries having enhancedmicroscopic and macroscopic mixing properties, which may be indicated bythe turbulent length scales in turbulent flow, in the vicinity of thescaffold and hence the catalyst, while also providing enhanced heattransfer properties.

A design process may comprise use of software, such as CAD geometrycreation software (e.g. SolidWorks). A design (or re-design) step, orprocess for preparing the static mixer, may comprise the use of softwareanalysis, such as CAD geometry creation software (e.g. SolidWorks)and/or CFD. For example, a design (or re-design) step, or process forpreparing the static mixer, may comprise the following steps:

1a. Determine an initial configuration for the scaffold of the CSM usingsoftware, for example CAD geometry creation software. An initialconfiguration may be determined based on a desired particularcharacteristic such as maximum surface area or those that are moresuitable for a particular metal deposition process, such as line ofsight accessibility for cold spraying.

1b. Optionally prepare a 3D physical model of the scaffold or CSM withthe initial configuration from step 1a.

1c. Optionally investigate and determine the suitability of theconfiguration of the CSM for manufacturing such as for 3D printing, coldspraying or electroplating. If changes are desired, the previous stepcan be repeated.

1d. Convert to a format readable by CFD software, for example an “stl”file format.

A further step may be provided comprising a CFD modelling softwarepackage (e.g. Flow-3D, ANSYS CFX, ANSYS Fluent). The CFD modellingprocess may comprise one or more of the following steps:

2a. Import configuration or geometry file (e.g. in STL format) into theCFD modelling software.

2b. Form a mesh to model the geometry, for example the entire geometryof the reaction chamber is broken down into finite volumes within eachof which the fluid dynamics equations are solved.

2c. Assign material properties;

2d. Assign physics—determine what processes are operating, e.g.turbulence effects, surface tension effects, heat transfer, etc.

2e. Optionally assign tracer particles—e.g. if we want to see how themixing is taking place.

2f. Assign initial conditions, for example velocity and pressure at theinlet, temperature if required, kinetic energy if required.

2g. Assign boundary conditions, which inform the software what happensat the external boundaries of the mesh, i.e., where is the inlet,outlet, walls, symmetry, etc.

2h. Assign mathematical parameters, which guide the solution process sothat results can be obtained in a reasonable length of time at theaccuracy level desired.

2i. Post-process—assess results (e.g. turbulent length scales,temperatures).

A method of preparing a static mixer comprising a scaffold usingcomputational fluid dynamics (CFD) software for enhancing theconfiguration of the scaffold for a pre-determined catalytic applicationmay comprise the steps of:

1a. determining an initial configuration for the scaffold using CADgeometry creation software;

1b. optionally preparing a 3D physical model of the scaffold with theinitial configuration from step 1a;

1c. optionally determining the suitability of the configuration of thescaffold for additive manufacturing and surface deposition techniques,and optionally repeating steps 1a to 1c;

1d. converting first electronic data from the CAD geometry software tosecond data in a format readable by CFD software; and

2. performing a CFD modelling process.

In an embodiment, step 2 of the above method may comprise steps of:

2a. importing the second data into CFD software;

2b. forming a mesh to model the geometry; and

2c. assigning material properties and assessing results.

The design process may also comprise an iterative approach to optimiseor enhance at least one of performance, durability, manufacturability,or scaffold suitability for catalytic coating. For example, if theresults can be enhanced by certain changes to the geometry, then changes(based on knowledge of fluid dynamics) can be made to the geometry andthe design optimisation procedure repeated.

The initial geometry may be chosen and optimised to enhance variouscharacteristics of the static mixer element, such as the specificsurface area, volume displacement ratio, line-of-sight accessibility forcold-spraying, strength and stability for high flow rates, suitabilityfor fabrication using additive manufacturing, or to achieve a highdegree of chaotic advection, turbulent mixing, catalytic interactions,or heat transfer. These characteristics, as well as any othercharacteristics of interest, may be weighted based on their relativeimportance to a particular application, and the design optimisationprocess can be directed towards enhancing the characteristics which aregiven more weight.

It will be appreciated that mixing refers to the process by which two(or more) separate constituents of the flow (i.e. different chemicalspecies or scalar constituents with different values, e.g. temperature)are brought together eventually and interact at a molecular level.

In the above diagram, the straight, parallel black lines arestreamlines, which are parallel to the mean flow. In laminar flow thefluid particles follow the streamlines exactly, as shown by the lineardye trace in the laminar region. In turbulent flow eddies of many sizesare superimposed onto the mean flow. When dye enters the turbulentregion it traces a path dictated by both the mean flow (streamlines) andeddies. Larger eddies carry the dye laterally across streamlines.Smaller eddies create smaller scale stirring that causes the dyefilament to spread (diffuse). It is the diffusion that creates the localmixing of constituents that are transported to various locations bylarger eddies.

The description of turbulence requires at least two quantities: 1. theintensity of turbulence indicated by the “turbulent kinetic energy” inthe turbulent fluctuations, and 2. the scale around which this energy isconcentrated, represented by the peak in the turbulence spectrum, orequivalently the “turbulence length scale”. A flow with a higherturbulent kinetic energy would therefore involve more vigorous mixingwhilst a flow with a higher turbulent length scale would indicate thatmixing occurs across a wider region.

The CFD procedure also enables further complexities to be considered,such as fluid temperature and associated property of the catalyticstatic mixers in flattening out temperature gradients, two-componentflows including gas bubbles, and micro-mixing models which will increasethe resolution of models and provide an indication as to how mixingoccurs at the molecular level (which is the length scale for chemicalreactions).

Catalyst Screening Method

There is also provided a method of screening a catalyst or catalystmaterial for catalytic reactivity using a static mixer element or systemas described herein, comprising the steps of:

providing a continuous flow chemical reactor comprising a static mixercomprising a predetermined catalyst or catalyst material;

operating the reactor at a predetermined setting; and

determining the % of product obtained from an output stream.

The catalyst screening method may be used to determine an effective oroptimal catalyst material for use in a predetermined reaction orreaction type, and for example in a given chemical flow reactoroperating under predetermined conditions or at a predetermined setting.The screening method may also be used to determine whether a specificcatalyst is effective or advantageous when used in a particularapplication. A number of different catalyst materials may be selectedand screened for a particular application in order to determine whichprovides the best yield or is most effective for the particularapplication. Each particular application may include any of the chemicalreactors described herein, set to any suitable operating configurationsuch as any of the operating conditions described herein, in order toestablish any of the reactions or reaction types described herein. Thecatalyst materials selected for screening may comprise any potentiallysuitable catalysts, such as any of the catalysts described herein or acompound comprising any of the catalysts described herein describedherein. The catalyst materials may be coated onto the surface of astatic mixer scaffold using any of the deposition methods describedherein, and the screening method may also be used to compare theeffectiveness of different deposition methods instead of or as well ascomparing different catalyst materials.

EXAMPLES

The present disclosure is further described by the following examples.It is to be understood that the following description is for the purposeof describing particular embodiments only and is not intended to belimiting with respect to the above description.

Referring to FIG. 1 and Table 1, a number of different static mixerswere manufactured for experimental purposes each in a set of fouridentical static mixers for operation in series together in a continuousflow hydrogenation reactor. Ni-EP-CoCr-A-P2-1 is a 3D printed staticmixer, containing a nickel catalyst layer (Ni) that was electroplated(EP) on a cobalt chromium alloy scaffold (CoCr) with a scaffold designconfiguration A-P2-6. Ni-EP-Ti-A-P2-3 is a 3D printed static mixer,containing a nickel catalyst layer (Ni) electroplated (EP) on a titaniumscaffold (Ti) with a scaffold design configuration A-P2-3.Ni-CS-Ti-A-P2-1 is a 3D printed static mixer, containing a nickelcatalyst layer (Ni) that was cold sprayed (CS) on a titanium scaffold(TI) with a scaffold design configuration A-P2-1. Ni-CS-SS-C-R1-4 is astatic mixer, containing a nickel catalyst layer (Ni) that was coldsprayed (CS) on a stainless steel (SS) scaffold with a scaffold designconfiguration C-R1-4. Pt-EP-Ti-A-P1-5 is a 3D printed static mixer,containing a platinum catalyst layer (Pt) that was electroplated (EP) ona titanium scaffold (Ti) with a scaffold design configuration A-P2-2.

TABLE 1 Static mixer (SM) used in the experiments described below.m_(CSM) m_(cat) V_(displaced) V_(reactor) ϕ CSM ident [g] [g] [ml] [ml][%] Ni-EP-CoCr-A-P2-6 24.4 1.0 3.1 13.9 81.7 Ni-EP-Ti-A-P2-3 11.5 N/V2.7 14.3 84.3 Ni-CS-Ti-A-P2-1 11.3 2.0 N/V N/V N/V Ni-CS-SS-C-R1-4 15.63.3 2.0 15.0 88.2 Pt-EP-Ti-A-P1-5^(†) 16.2 N/V 2.9 14.1 83.2X-X-Ti-A-P2-2 9.6 0.0 2.1 14.9 87.5 m_(CSM) = total mass of set of fourCSMs (the continuous flow reactor can house four CSMs at a time);m_(cat) = total mass of catalyst on this set of CSMs; V_(displaced) =total volume displacement of this set of four CSMs; V_(reactor) =reactor volume left when CSMs are inserted into the reactor module(empty volume = 17 ml); ϕ = porosity of the CSM (see equation 1).^(†)The set Pt-EP-Ti-A-P1-5 consisted only of three catalytic mixerscoated with Pt, and a fourth uncoated, non-catalytic static mixer.

The porosity of the CSM, 4), can be calculated using the following:

$\begin{matrix}{\Phi = {\frac{V_{reactor}}{4\left( {\frac{\pi}{4}d^{2}l} \right)} = {\frac{{\pi\; d^{2}l} - V_{displaced}}{\pi\; d^{2}l} = {1 - \frac{V_{displaced}}{\pi\; d^{2}l}}}}} & (1)\end{matrix}$

Additive Manufacture of Metal Scaffolds

All SMs were manufactured on the Arcam A1 electron beam 3D printer usingeither TiAl64V powders (45-105 micrometre diameter range) or thecobalt-chrome superalloy FSX-414 powders. The machine process parameterswere set by trial and error for FSX-414 but were known for Ti6Al4Vthrough previous experience with builds on the alloy. The catalyst wasthen either cold sprayed or electro-deposited onto the metal scaffolds.

Cold Spraying of Catalyst onto the Metal Scaffolds

Twelve different scaffolds were coated using different cold sprayingsystems and processes as shown in Table 2. The conditions which producedthe most optimal metallurgical bonding and porosity in the catalyticlayer are given in rows 8 to 11.

TABLE 2 Cold spray conditions for nickel coatings. Gas Gas Traverse FeedStand- Temp Press Speed Total Rate off Weight g ° C. Mpa mm s⁻¹ PassesTurns rpm mm Ni Loading  1 4.56 700 3.5 200 8 2 sides (halves) 1 30 0.65 2 3.51 700 3.5 200 2 1 side 1 30 0.16  3 3.30 700 4.0 200 8 2 sides(halves) 1 30 0.90  4 2.88 700 4.0 200 4 1 side 1 30 0.58  5 2.30 7004.0 200 4 4 sides (quarters) 1 30 1.56  6# 2.28 700 4.0  400* 4 4 sides(quarters) 0.5 30 0.53  7# 2.47 700 4.0 400 4 4 sides (quarters) 0.5 300.34  8# 2.31 700 4.0 300 4 4 sides (quarters) 0.5 30 0.53  9# 2.30 7004.0 300 4 4 sides (quarters) 0.5 30 0.57 10 3.08 700 4.0 300 4 4 sides(quarters) 0.5 30 0.55 11 3.15 700 4.0 300 8 4 sides (quarters) 0.5 301.00 12** 3.12 700 4.0 300 4 4 sides (quarters) 0.75 30 1.08 13## 3.08700 4.0 300 4 4 sides (quarters) 0.75 30 0.67 *1^(st) Pass at 200 mm/s;# Used for hydrogenation trials; **1^(st) pass at 1.0 rpm feed; ##1 sidemoved during spray edge only sprayed.

In the cold spray method the scaffold was held in an aluminium tubewhich was opened on one side as shown in FIG. 7A. This arrangementallowed the scaffold to be cold sprayed effectively and at the same timeprevented the force of the carrier gas from fracturing of the scaffold.A Plasma Giken PCS-1000 cold spray system, fitted with a water-cooled,one-piece, tungsten carbide nozzle with a 3 mm throat, was used to spraynickel powder (−20 to +10 micron spherical particles). The cold sprayparameters given in rows 8 to 11 of Table 2 produced coatings with highporosity and high metallurgical bonding according to the SEM and opticalpictures of the cold sprayed 3D scaffolds shown in FIG. 8A to 8D.

Electro Deposition of Catalyst onto the Metal Scaffold

In the electrodeposition method, copper, nickel and platinum weredeposited onto Ti-6Al-4V alloy or Co—Cr static mixer scaffolds using anelectrochemical flow cell. The SM becomes the cathode and sits at thecentre of the cell surrounded by the anode. The concentric geometrymaintains an even current distribution.

Electrodeposition is useful for this application because deposition isnot restricted to line of sight, many metals and alloys are possibleincluding precious metals that are hard to deposit efficiently usingother methods, and the process is quick and inexpensive. The procedureinvolved selecting suitable solution chemistry, surface pre-treatment ofthe mixer, developing effective pulsed current profiles and postdeposition cleaning. Each different scaffold mixer material andcatalytic coating may require different plating conditions. When theconditions are carefully controlled, substantially uniform coatings ofthe catalytic metal were produced FIG. 9A and FIG. 9B.

Flow Reactor Experiments

The continuous flow reactor set-up is shown in the flow diagram of FIG.10 . The set-up consists of the reactor module, which is housing thecatalytic inserts, a liquid feed line, including a liquid reagent pump(Gilson 305 HPLC pump), a gas feed line, and electronic process controland data logging.

As depicted in FIG. 10 , the reactor module contains four reactor zones,each of which are made from 15 cm long stainless steel tubing (Swagelok,8 mm OD, 6 mm ID). It also contains five temperature probes (PT-100),situated before and after each reactor zone.

The reactor module can be dismantled easily in order to facilitatechange-over of the catalytic inserts. The reagent pump supplies thesubstrate feed stream, which contains a solution of the startingmaterial substrate, neat or in a solvent. The hydrogen gas is suppliedfrom a hydrogen cylinder (G-type cylinder) and mixed with the liquidstream in a T-piece. The combined stream then flows through a liquid-gasdisperser (Swagelok SS-4TF-90) before it enters the reactor. Thepressure at inside the reactor is regulated by a diaphragm back pressureregulator (BPR, Swagelok KBP1J0A4D5A20000), which is situated at theoutlet of the reactor.

After passing through the BPR, the hot effluent can optionally be cooledin a coil type heat exchanger, which is operated with tap water as thecooling fluid. The product stream is then collected in a bottle or flaskfor further post processing.

Further safety components and process control and monitoring equipmentis installed in the rig: safety pressure relief valve at reactor inlet(Swagelok, SS-4R3A); safety shut-down valve in the gas line (Bürkert,2/2-way solenoid valve 6027-A03); flash-back arrestor (Witt 85-10) inthe gas line; mass flow controller in the gas line (Bronkhorst, MFCF-201CV-500); and pressure sensors in the liquid line, gas line and atthe inlet of the reactor (pL, pG, pR).

The reaction occurs at the solid-liquid interface of the catalyticinserts, inside the four reactor zones. The operation of the reactorsystem is controlled by LabView software, which was written in house.Temperature, pressure and gas flow rate data is also monitored by theLabView control program.

The above mentioned configuration is tailored for hydrogenationreactions; with minimal changes to the apparatus, the reactor system canalso be used for metal catalysed C-C coupling reactions, oxidations orother organic reactions.

In order to evaluate this reactor for hydrogenation reactions, a seriesof experiments were conducted investigating the hydrogenation of oleicacid (OA, see Scheme 1), vinyl acetate (Vac), and cinnamaldehyde (CAL,see Scheme 2).

A typical hydrogenation reaction on the above reactor configuration wasconducted as follows. First the catalytic inserts inside the reactorwere activated by flowing hydrogen over them at 16 bar, 180° C. and agas flow rate of 100 mL_(N)/min. The activation was conducted forseveral hours (between 2.5 and 6 h). After activation the reactor wasflushed with the solvent, ethyl acetate (EtOAc), using the liquidreagent pump. The substrate, oleic acid was dissolved in ethyl acetateto a concentration of 1 mol/L.

Before start of the reaction, the hydrogen gas was introduced, togetherwith the washing solvent, and the parameters for the reaction wereadjusted: pressure inside reactor, pR=16 bar, liquid flow rate,VG,R=0.25 ml/min, gas flow rate inside the reactor, VG,R=2.05 mL/min(VG,N=21.2 mL_(N)/min), reactor temp, TR=140° C.

Once pressure and temperature had stabilised, the substrate (OA) was fedinto the reactor by changing over the reagent pump from pure solvent tothe prepared clear stock solution. The combined flow rate through thereactor was 2.3 mL/min, resulting in a mean residence time, τ, of 6 min.6 min after start of the reaction, the product was collected at theoutlet of the reactor in several fractions. The fractions containingproduct were combined and the solvent removed by evaporation.

A white waxy solid (stearic acid) was recovered after solvent removal,which was then analysed by 1H-NMR and GC. Reaction conversions werecalculated from 1H NMR spectra, which were recorded on a Bruker AC-400spectrometer in deuterated chloroform (from Cambridge IsotopeLaboratories Inc.). The residual solvent peak at δ=7.26 ppm was used asan internal reference. Product compositions were analyzed by GC-FID andGC-MS.

The GC-FID results were also used to confirm NMR conversions and tocalculate GC-based yields. GC-mass spectra were obtained with a PerkinElmer Clarus 600 GC mass spectrometer using electron impact ionizationin the positive ion mode with ionization energy of 70 eV. The gaschromatography was performed with a Perkin Elmer Elite-5MS GC column (30m×0.25 mm ID, 0.25 μm film thickness), with a temperature program of 40°C. for 2 minutes, then heating at 10° C./min to 280° C. where thetemperature was held for 4 minutes with a split ratio of 70, an injectortemperature of 250° C. and the transfer line was set to 250° C.Ultra-high purity helium was used as the carrier gas with a flow rate of0.7 ml/min.

GC-FID analysis was performed on an Agilent 6850 Series II gaschromatograph with a split/splitless inlet and a detector temperature of250° C. Separation was done on a Grace BPX5 capillary column (25 m×0.32mm ID, 0.50 μm film thickness), with a temperature program of 40° C. for2 minutes, then heating at 10° C./min to 280° C. where the temperaturewas held for 4 minutes with a split ratio of 50 and an injectortemperature of 200° C. High purity helium was used as the carrier gaswith a flow rate of 2.4 ml/min. The reagents oleic acid was obtainedfrom Sigma Aldrich; the solvents ethyl acetate (EtOAc), ethanol (EtOH),isopropanol (iPrOH) were obtained from Merck KGaA. All reagents andsolvents were used without further purification.

Table 3 shows experimental data from the hydrogenation reactions usingoleic acid, vinyl acetate and cinnamaldehyde, and the CSMs described inTable 1.

TABLE 3 Experimental data from the hydrogenation reactions using oleicacid (OA); vinyl acetate (VAc) and cinnamaldehyde (CAL). Pressure Temp.V_(tot) Conversion Catalyst Substrate [bar] [° C.] [ml/min] G/L τ [min][%]  1 Ni-CS-Ti-A-P2-1 OA 16 140 2.3 3.6 6.4 16  2 Ni-CS-Ti-A-P2-1 OA 16140 2.3 6.7 6.4 20  3 X-X-Ti-A-P2-2 OA 16 140 2.3 3.6 6.5  0  4Ni-EP-Ti-A-P2-3 OA 16 140 2.3 3.6 6.2  9  5 Ni-CS-SS-C-R1-4 OA 16 1402.3 3.6 6.5 26  6 Ni-CS-SS-C-R1-4 OA 16 140 2.3 0.9 6.5  1  7Ni-CS-SS-C-R1-4 OA 16 140 2.3 2.8 6.5 20  8 Ni-CS-SS-C-R1-4 OA 16 1402.3 8.2 6.5 44  9 Ni-CS-SS-C-R1-4 OA 16 140 2.3 10.5 6.5 55 10Ni-CS-SS-C-R1-4 OA 16 140 2.3 5.6 6.5 27 11 Pt-EP-Ti-A-P1-5 OA 16 1402.3 3.6 6.1 21 12 Ni-EP-CoCr-A-P2-6 OA 16 140 2.3 3.6 6.0  1 13Ni-CS-SS-C-R1-4 VAc 22 140 3.0 5.0 5.0 74 14 Pt-EP-Ti-A-P1-5 VAc 16 1403.0 5.0 4.7 100  15 Ni-EP-CoCr-A-P2-6 VAc 20 140 3.0 5.0 4.6 15 16*Pt-EP-Ti-A-P1-5 CAL 20 140 3.0 5.0 4.7  89* V_(tot) = total volumetricflow rate through reactor at the given temperature and pressure(combined gas and liquid flow); G/L = ratio of gas to liquid flow; τ =hydraulic residence time inside reactor; the solvent was EtOAc and theconcentration of substrate was between 1 and 2 mol/L; *CAL was convertedto 89%, giving a range of different hydrogenation products: HCOH 16%,COH 61%, HCAL 7%, CAL 11%, others 5% (see Scheme 2).

Table 3 shows a comparison of the performance of the different preparedsets of SMs from Table 1 under similar conditions. It can be seen thatthe G/L ratios and selection of scaffold material, coating method andcatalysts can have an effect on the hydrogenation (conversion %) of thesubstrate. The control experiment using an uncoated set of SMs(X-X-Ti-A-P2-2) did not result in any hydrogenation of the oleic acid.The highest observed conversion in this set of experiments for oleicacid was 55% (entry 9 in Table 3). The product streams of theexperiments resulting in ˜10% conversion or higher were cloudy and aftersolvent removal a white waxy solid was obtained.

The parameters G/L and reactor pressure were found to have a significantimpact on the performance of the reactor, hence these two parameterswere studied in more detail. FIG. 11 presents a parameter study for thehydrogenation of OA on Ni-CSMs, showing a linear increase of conversionwith G/L where higher amounts of hydrogen should increase conversion. Asimilar trend was observed, when the reactor pressure was varied (seeFIG. 12 ) for the hydrogenation of VAc. Here, three different catalystsets were tested, one of which resulted in very high conversions atpressures above 20 bar, where an asymptotic deviation from the otherwiselinear behaviour was observed. Table 3 contains a condensed set of theseexperiments, conducted at varying conditions and with six differentcatalyst sets. Entry 3 is a control experiment using a set ofnon-catalytic mixers; here no conversion was observed. The productstreams of the experiments with OA resulting in >10% conversion werecloudy and after solvent removal a white waxy solid was obtained. Thismaterial was noticeably different from the clear stock solution whichwas pumped into the reactor. This is a clear indicator of the success ofthe hydrogenation reaction, as a waxy solid, stearic acid, was formedfrom a viscous oil, oleic acid.

The influence of activation on reactor performance and long termperformance of the catalyst was studied by setting up a series of repeatreactions. Here, one set of conditions was chosen and the same reactionwas performed multiple times, using the Pt-CSM set, Pt-EP-Ti-A-P1-5.After a certain number of repeats, the catalyst was activated againbefore further experiments were conducted. FIG. 13 shows the resultsfrom this study, demonstrating that with a freshly activated catalyst,the conversions were higher, namely between 88.3 and 100%, whilewithout, they dropped as low as 65.3%. In general, it can be stated thatthe catalyst retained catalytic activity even after multiple runs, andgenerally produced moderate to high conversions, generally ˜20% lowerthan a freshly activated catalyst.

Entry 16 in Table 3 shows the hydrogenation of cinnamaldehyde, asubstrate containing two reactive moieties, namely a carbonyl group anda double bond. Here Pt-CSMs were used, investigating the selectivity ofthis catalyst system for the two reactive groups. The experimentresulted in a total conversion of CAL of 89%, whereby the majority, 61%was hydrogenated to the corresponding unsaturated alcohol, cinnamylalcohol (COH). The hydrogenated aldehyde, hydrocinnamaldehyde (HCAL) wasfound in 7% and the fully hydrogenated product hydrocinnamyl alcohol(HCOH) was found in 16% (unreacted CAL: 11%, other unidentifiedproducts: 5%). This result shows that the Pt catalyst was more activetowards reduction of the aldehyde than the double bond.

FIG. 14 shows a comparison of the six different CSM sets used withinthis study for the two different substrates OA and VAc. While theconversions for OA under these comparative conditions was relatively lowfor all catalysts, the one that performed best was Ni-CS-SS-C-R1-4 at26%, and this was also the CSM set containing the highest amount ofnickel. The good performance of this set for the hydrogenation of OA isdue to the applied catalyst deposition method and to the 3D design ofthe mixer. Ni-CS-SS-C-R1-4 was the best combination of both, containinga relatively thick Ni-layer on top of a ribbon-like mixer design.Compared to the porous 3D-printed structures shown in FIG. 1 , thisdesign was relatively flat and non-porous, which was well suited forline-of-sight deposition techniques such as cold spraying, resulting ina complete coverage of the mixer with nickel. In contrast, a fullcoverage of the entire surface of porous designs, including the internalpores, is not as feasible by cold spraying. Electroplating on the otherhand, being a submersion-based deposition method, is understood to covereven internal pores of these structures. However, the layers that werecreated by electroplating, where not as thick for the herein chosenconditions and also not as porous as the ones applied by cold-spraying,hence the activity of the sets Ni-EP-CoCr-A-P2-6 and Ni-EP-Ti-A-P2-3were not as high as their cold spray counterparts. For the reactionswith Vac, the Pt-CSM set, Pt-EP-Ti-A-P1-5, outperformed all others,including Ni-CS-SS-C-R1-4. Here we believe that the more active catalystmetal Pt increases the reactivity of the system significantly whencompared to the Ni-based CSMs, even though the later contained a largeramount of catalyst.

The Ti alloy mixers appeared to be more susceptible to hydrogenembrittlement. After extended use with gaseous hydrogen, the mixersbecame porous, lost mechanical stability and started to disintegrate.This became apparent when mixers that have been used for a large numberof experiments were removed from the reactor to replace them with freshones. In one incident, the mixers fell apart and could only be removedfrom the reactor pipe in form of coarse metal granules. In comparison noembrittlement was observed with the CoCr alloy CSMs.

Preliminary leaching tests were performed on a set of cold-sprayed NiCSMs using ICP-OES. For this the reactor was operated for an extendedperiod of time at steady state conditions, processing a total of over 1L of stock solution. The product stream contained on average 157 ppb Ni,621 ppb Fe and 34 ppb Cr. These results show that the Ni catalyst isvery well bound to the substrate, and that the majority of the solublemetal contamination was likely to come from the stainless steel reactortubing rather than from the catalytic layer itself, and that the totalamount was very low.

Use of Computational Fluid Dynamics (CFD) to Optimise SM Design

CFD was applied to the design of SMs to ensure that the additivelymanufactured versions would be better at mixing the reactants as well aspresent the flowing reactants with the maximum amount ofcatalytic-deposited surface area. The first design was conceived as amesh that had a helical geometry with an alternating clockwise andcounter-clockwise direction to disrupt the flow and create turbulence(FIGS. 4A and 4B).

CFD analysis showed that this geometry had a significant limitation inthat there were straight channels available for the flow to keep to fromthe start to the end—which meant it experienced minimal disruption.

The geometry may be improved by changing it to avoid straight channelsthat run parallel to the flow.

Additional Flow Reactor Experiments

Additional catalytic static mixers were prepared and tested in either a4 static mixer series (4 modules together in series, which is referredto as “4-set”) or 12 static mixer series (12 modules together in series,which is referred to as “12 set”). Three systems were tested beingPd-EP-SS-A-3-7 (4 set, Palladium-Electrospray coating, stainless steeland aluminium alloy substrate), Ni-CS-SS-A-2-8 (12 set, Nickle-ColdSpray coating, stainless steel and aluminium alloy substrate), andPd-EP-SS-A-2-9 (12 set, Palladium-Electrospray coating, stainless steeland aluminium alloy substrate).

Transfer Hydrogenation of Nitro Compounds to Amines using Mark 1 Reactor(4-Set System)

Ammonium formate in methanol in the presence of a palladium coatedstatic mixer was used to generate hydrogen in situ. A solution ofp-nitroanisole (153 mg, 1 mmol), and ammonium formate (315 mg, 4.6 mmol)in MeOH (3 mL) was passed through the Mark I reactor, fitted withcatalytic static mixer Pd-EP-SS-A-3-7, and heated at 130° C. at 11.5bar, at a flow rate of 1 mL/min. The eluent was collected and thesolvent was evaporated to give p-methoxyaniline at 100% conversion.

Additional reactions were performed in a similar manner with parametersand conversions shown in Table 4.

TABLE 4 Temp Pressure Catalyst Substrate ° C. (bar) Product Conversion %1 Pd-EP-SS-A-3-7 4-nitroanisole 130 11.5 4-methoxyaniline 100 2Pd-EP-SS-A-3-7 2-nitroanisole 130 11.5 2-methoxyaniline 10 3Pd-EP-SS-A-3-7 3-nitroanisole 130 11.5 3-methoxyaniline 20 4Pd-EP-SS-A-3-7 nitrobenzene 130 11.5 aniline 31 5 Pd-EP-SS-A-3-7nitrobenzene 130 20 aniline 36 6 Pd-EP-SS-A-3-7 4-nitrotoluene 130 20p-toluidine 87 7 Pd-EP-SS-A-3-7 4-nitrophenol 130 20 4-aminophenol 17Rxns run in MeOH. Flow rate = 1 ml/min. Concentration = 0.33M.

Dehalogenation of Acetophenone Via Transfer Hydrogenation Using Mark 1Reactor

Ammonium formate in methanol in the presence of a palladium coatedstatic mixer was used to generate hydrogen in situ. A solution of4-bromo acetophenone (100 mg, 0.5 mmol), and ammonium formate (510 mg,7.5 mmol) in MeOH (3 mL) was passed through the Mark I reactor, fittedwith catalytic static mixer Pd-EP-SS-A-3-7, and heated at 130° C. at 12bar, at a flow rate of 1 mL/min. The eluent was collected and thesolvent was evaporated to give acetophenone (65%), 4-bromo acetophenone(33%), and 2% of the acetophenone homodimer.

Mark 2 Reactor

The Mark 2 continuous flow reactor set-up is similar to that for theMark 1 reactor, with a liquid line feed, a liquid reagent pump (Gilson305 HPLC pump), a gas feed line and electronic process control and datalogging. The Mark 2 reactor however houses 12 catalytic inserts insteadof 4.

Catalysts may be pre-activated by passing hydrogen gas through thereactor, for example at 20 bar for 1 h at 120 deg C.

For given substrate parameters such as temperature, solvent, pressure,liquid flow rate, hydrogen gas flow rate, and concentration, these maybe varied to determine the best reaction conditions for conversion ofthe substrate to product.

This process was used for a variety of substrates with the best reactionconditions listed in Table 5.

Reduction of Vinyl Acetate to Ethyl Acetate Using Mark 2 Reactor (seeEntry 1, Table 5)

A solution of vinyl acetate (30 mL, 2M in EtOH) was passed through theMark 2 reactor, fitted with catalytic static mixer Ni-CS-SS-A-2-8, at120° C. at 24 bar, at a liquid flow rate of 1 mL/min and a hydrogen gasflow rate of 5 mL/min. The eluent was collected to give ethyl acetate at100% conversion.

Additional reactions were performed in a similar manner with parametersand conversions shown in Table 5.

TABLE 5 Conc. Press. V_(L) V_(G) Catalyst Substrate Solvent Mol/L (bar)ml/min ml/min Conversion 1 Ni-CS-SS- Vinyl acetate^(a) EtOH 2 24 1 5 100ethyl acetate A-2-8 2 Ni-CS-SS- Acetophenone EtOH 2 24 1 5 61-phenylethan-1-ol A-2-8 3 Ni-CS-SS- Phenylacetylene EtOH 2 16 1 5 100ethyl benzene A-2-8 4 Ni-CS-SS- Benzyl Cyanide^(a) EtOH 0.5 24 1 10 43phenylethylamine A-2-8 5 Pd-EP-SS- Vinyl Acetate^(a) EtOH 2 16 1 5 100ethyl acetate A-2-9 6 Pd-EP-SS- Acetophenone EtOH 1 24 1 5 541-phenylethan-1- A-2-9 ol 7 Pd-EP-SS- Cinnamaldehyde EtOH 1 24 2 8 603-phenylpropanal A-2-9 37 3-phenylpropanol 8 Pd-EP-SS- Benzyl CyanideEtOH 1 24 1 8 78 2-phenylethan-1- A-2-9 amine 9 Pd-EP-SS- 4-nitroanisoleEtOAc 1 20 2 8 30 4-methoxy aniline A-2-9 10 Pd-EP-SS- 3-nitroanisoleEtOAc 1 20 2 8 87 3-methoxy aniline A-2-9 11 Pd-EP-SS- 2-nitroanisoleEtOAc 0.5 20 1 4 100 2-methoxy A-2-9 aniline 12 Pd-EP-SS- 4-nitrotolueneEtOAc 1 24 2 8 98 4-methyl aniline A-2-9 13 Pd-EP-SS- Azobenzene EtOAc 120 2 8 61 aniline A-2-9 14 Pd-EP-SS- 1-Bromo-3- EtOAc 0.5 20 1 4 803-bromoaniline A-2-9 nitrobenzene 15 Pd-EP-SS- (E)-(3- EtOAc 0.5 20 1 42 propylbenzene A-2-9 chloroprop-1- 59 1- en-1-yl)benzenepropenylbenzene 16 Pd-EP-SS- 1-chloro-4- EtOAc 0.5 20 1 4 704-chloroaniline A-2-9 nitrobenzene 17 Pd-EP-SS- 1-chloro-2- EtOAc 0.5 201 4 86 2-chloroaniline A-2-9 nitrobenzene 18 Pd-EP-SS- 1-chloro-3- EtOAc0.5 20 1 4 94 3-chloroaniline A-2-9 nitrobenzene 19 Pd-EP-SS-4-chloro-4- EtOAc 0.5 20 1 4 62 1-chloro-4- A-2-9 vinylbenzeneethylbenzene 20 Pd-EP-SS- 4-chloro-2- EtOAc 0.5 20 1 4 61 2-amino-4-A-2-9 nitrobenzaldehyde chlorobenzaldehyde All reactions were run at120° C.

An example of the optimisation process is shown in FIG. 15 for thereduction of phenylacetylene to ethylbenzene (see Entry 3, Table 5). Itwas found that more advantageous conditions of 0.5 mL/min liquid flowrate, 5 mL/min hydrogen gas flow rate, 24 bar at 120° C. were requiredfor 100% conversion of phenylacetylene to ethylbenzene.

FIG. 16 shows that for the conversion of vinyl acetate to ethyl acetateusing Ni-CS-SS-A-2-8 and the Mark 2 reactor an optimum temperature of120° C. was required to achieve 100% conversion (see entry 1, Table 5).

Leaching Experiments

To analyse potential leaching of the catalysts from the catalytic staticmixers the outlet of multiple experiments was collected, concentratedand ICP-OES performed. The two following tables show catalytic staticmixer leaching results when steady state appeared for both Nickle andPalladium catalysts and illustrates that there is minimal leaching ofcatalyst from the static mixers during reactions.

Ni-CS-SS-A-2-8 Cr Fe Ni ppm total 0.04 0.78 0.18 Concentration 1.2724.13 5.02 (μmol/L)

Pd-EP-SS-A-2-9 Cr Fe Ni Pd ppm total 0.24 0.63 0.30 <0.001 Concentration8.12 19.66 8.56 <0.025 (μmol/L)

The invention claimed is:
 1. A continuous flow chemical reactor for usein reaction of one or more fluidic reactants, the reactor comprising:one or more reaction chamber sections in fluidic communication with eachother, each reaction chamber section housing an additive manufactured,removable static mixer element configured as an integral modular insertfor insertion into each reaction chamber section, wherein the aspectratio (L/d) of the reactor is at least about 50, each static mixerelement comprising catalytically reactive sites and an integral scaffolddefining a plurality of similar structures repeated periodically alongthe longitudinal axis of the scaffold to form a continuous lattice ofinterconnected segments, each segment comprising polygonal prisms,helical segments or a helicoid providing a plurality of apertures andpassages configured for enhancing mixing, contact of the fluidicreactants with the catalytically reactive sites and heat transfer, byredistributing fluid in directions transverse to the main flow throughthe plurality of passages by changing or splitting the localized flowdirection by more than 200/m, corresponding to a number of times withina given length along a longitudinal axis of the static mixer element,and, in use, configured to provide a transverse temperature differentialof less than about 10° C./mm and a pressure drop across the reactionchamber section (in Pa/m) of less than about 100,000 with a volumetricflow rate of at least 0.1 ml/min; one or more reactant inlets for supplyof the one or more fluidic reactants to the one or more reaction chambersections; and one or more outlets in fluidic communication with thestatic mixer element for receiving an output stream comprising a productof the reaction wherein at least a portion of a surface of the scaffoldcomprises a catalytic material for providing the surface withcatalytically reactive sites, and wherein the catalytically reactivesites are provided by at least one of: the scaffold being formed from acatalytic material; a catalyst material being intercalated, interspersedand/or embedded with at least part of the scaffold; or at least a partof the surface of the scaffold comprising a coating comprising acatalyst material.
 2. The continuous flow chemical reactor of claim 1wherein the aspect ratio (L/d) of each static mixer element is at least25, and arranged in each reaction chamber section in a series of one ormore static mixer elements to a total aspect ratio (L/d) of at least 75.3. The continuous flow chemical reactor of claim 1, wherein at least apart of the surface of the scaffold comprises a coating comprising acatalyst material, the coating being an electrodeposition coating. 4.The continuous flow chemical reactor of claim 1, wherein at least a partof the surface of the scaffold comprises a coating comprising a catalystmaterial, the coating being a cold spray coating.
 5. The continuous flowchemical reactor of claim 1, wherein the catalytic material comprises ametal selected from at least one of iron, cobalt, copper, zinc, nickel,palladium, platinum, gold, silver, ruthenium, iridium, rhodium, titaniumvanadium, zirconium, niobium, tantalum, and chromium, or a metal alloy,cermet or metal oxide thereof.
 6. The continuous flow chemical reactorof claim 1, wherein the catalytic material comprises nickel or nickelalloy.
 7. The continuous flow chemical reactor of claim 1, wherein thescaffold comprises or consists of a metal, metal alloy, cermet and metaloxide.
 8. The continuous flow chemical reactor of claim 1, wherein thescaffold is provided in a mesh configuration having a plurality ofintegral units defining a plurality of passages configured forfacilitating mixing of reactants and heat transfer.
 9. The continuousflow chemical reactor of claim 1, wherein the scaffold is provided by alattice of interconnected segments configured to define a plurality ofapertures for promoting mixing of fluid flowing through the reactorchamber.
 10. The continuous flow chemical reactor of claim 1, whereinthe scaffold is configured for operating in a turbulent flow with aReynolds numbers (Re) of at least about
 2500. 11. The continuous flowchemical reactor of claim 1, wherein the scaffold is configured foroperating in a turbulent flow with a Reynolds numbers (Re) in a range ofabout 2500 to
 6000. 12. The continuous flow chemical reactor of claim 1,wherein the diameter (in mm) of each tubular reaction chamber sectionand housed catalytically active static mixer element is in the range of5 to
 150. 13. The continuous flow chemical reactor of claim 1, whereinthe aspect ratio (L/d) of the reactor is in the range of about 100 to500.
 14. The continuous flow chemical reactor of claim 1, wherein theaspect ratio (L/d) of each static mixer element is at least 15, andarranged in each reaction chamber section in a series of one or morestatic mixer elements to a total aspect ratio (L/d) of at least
 50. 15.The continuous flow chemical reactor of claim 1, wherein the reactorcomprises a heat exchanger system to allow control of the temperature ofthe reactor, chamber section, catalytic static mixer, or fluidiccomponents thereof, wherein the heat exchanger is separate to thecatalytic static mixer.
 16. The continuous flow chemical reactor ofclaim 1, wherein the aspect ratio (L/d) of the reactor is at least about75.
 17. The continuous flow chemical reactor of claim 1, wherein thereactor is a tubular continuous flow reactor comprising one or moretubular reaction chamber sections.
 18. A system for providing acontinuous flow chemical reaction comprising: a continuous flow chemicalreactor according to claim 1; a pump for providing fluidic flow for oneor more fluidic reactants and any products thereof through the reactor;one or more heat exchangers to allow for control of the temperature ofthe reactor, chamber section, static mixer, or fluidic componentsthereof, wherein the heat exchanger is separate to the static mixer; anda controller for controlling one or more of the parameters of the systemselected from concentration, flow rate, temperature, pressure, andresidence time, of the one or more fluidic reactants, or sources orproducts thereof.
 19. A process for synthesizing a product by catalyticreaction of one or more fluidic reactants, the process comprising thesteps of: providing a continuous flow chemical reactor according toclaim 1; providing at least a first fluidic reactant to the reactor viathe one or more reactant inlets; operating the chemical reactor, orcontrol means thereof, to provide flow and catalytic reaction of the atleast first fluidic reactant through the static mixer; and obtaining anoutput stream comprising a product of a catalytic reaction of the atleast first reactant.
 20. The process of claim 19, wherein the pressuredifferential across the static mixer (in Pa/m) is less than about10,000.
 21. The process of claim 19, wherein the pressure differentialof the volumetric flow rate is at least 1 ml/min.
 22. A process forpreparing an additive manufactured static mixer element for a continuousflow chemical reactor chamber, comprising the steps of: providing astatic mixer element configured as an integral modular insert forhousing within a reaction chamber section, the integral modular insertcomprising an integral scaffold defining a plurality of passages; andapplying a catalytic coating to at least a portion of the surface of thescaffold to provide the surface with a plurality of catalyticallyreactive sites, each static mixer element comprising catalyticallyreactive sites and an integral scaffold defining a plurality of similarstructures repeated periodically along the longitudinal axis of thescaffold to form a continuous lattice of interconnected segments, eachsegment comprising polygonal prisms, helical segments or a helicoidproviding a plurality of apertures and passages configured for enhancingmixing, contact of one or more fluidic reactants with the catalyticallyreactive sites, and heat transfer, by redistributing fluid in directionstransverse to the main flow by changing or splitting the localized flowdirection by more than 200 m^(↓), corresponding to a number of timeswithin a given length along longitudinal axis of the static mixerelement, and, in use, configured to provide a transverse temperaturedifferential of less than about 10° C./mm and a pressure drop across thereaction chamber section (in Pa/m) of less than about 100,000 with avolumetric flow rate of at least 0.1 ml/min.
 23. The process of claim22, wherein the static mixer element is configured as an integral modulefor housing within a tubular reaction chamber section.
 24. The processof claim 22, wherein aspect ratio (L/d) of the static mixer element isat least
 15. 25. The process of claim 22, wherein aspect ratio (L/d) ofthe static mixer element is at least 25.